docs: harden thesis architecture and evidence claims

docs/add/diagrams.md

@@ -21,6 +21,25 @@ flowchart LR
   Sources --> Python[Python Sources]
 ```
 
+## Layered Package Boundary
+
+> Package ownership view, not a runtime call graph.
+
+```mermaid
+flowchart TB
+  CLI[wf_cli] --> Transport[wf_transport_rpc_http]
+  Transport --> Server[wf_server]
+  Server --> API[wf_api]
+  API --> Artifacts[wf_artifacts]
+  API --> Core[wf_core]
+  API --> Platform[wf_platform]
+  Server --> MCP[wf_sources_mcp]
+  Server --> Python[wf_sources_python]
+  MCP --> Platform
+  Python --> Platform
+  Artifacts --> Platform
+```
+
 ## Workflow Lifecycle
 
 > Simplified view. For the detailed platform-domain version with source inventory
@@ -54,17 +73,32 @@ flowchart LR
 ## Workflow Core
 
 ```mermaid
-flowchart LR
+flowchart TD
-  Input[Input Schema] --> NodeUse[Node Use]
+  Start[Prepare Run] --> ValidateInput[Validate Workflow Input]
-  NodeSpec[NodeSpec Contract] --> NodeUse
+  ValidateInput --> Select[Select Ready Frame]
-  NodeUse --> Outcome[Declared Outcome]
+  Select --> Step{Step Type}
-  Outcome --> Edge[Graph Edge]
+  Step --> Node[NodeUse]
-  NodeUse --> StateWrite[State Write]
+  Step --> Condition[Condition]
-  StateWrite --> Reducer[Reducer]
+  Step --> Foreach[Foreach]
-  Reducer --> State[Workflow State]
+  Step --> Subgraph[Subgraph]
-  NodeUse --> Trace[Trace Frame]
+  Step --> Interrupt[Interrupt]
-  Interrupt[Interrupt] --> RunState[Stopped Run State]
+  Step --> Join[Join / Minimal Done Step]
-  RunState --> Resume[Resume]
+  Step --> End[End]
+  Node --> ResolveInput[Resolve Input Bindings]
+  ResolveInput --> Handler[Invoke NodeDef Handler]
+  Handler --> CheckOutcome[Check Declared Outcome]
+  CheckOutcome --> StatePatch[Build Reducer-Aware State Patch]
+  StatePatch --> Trace[Append Trace Frame]
+  Condition --> Trace
+  Foreach --> Trace
+  Subgraph --> Trace
+  Join --> Trace
+  Trace --> Route[Route By Outcome Edge]
+  Interrupt --> Stop[Persist Interrupt Request]
+  End --> Finalize[Project Workflow Output]
+  Route --> Select
+  Stop --> Resume[Resume Payload + Outcome]
+  Resume --> Route
 ```
 
 ## Platform Domain
@@ -79,10 +113,29 @@ flowchart LR
   DeploymentValidation --> Run[Workflow Run]
   Run --> RunRecord[Run Record]
   Run --> Trace[Trace Slice]
-  RunRecord --> Resume[Resume]
+  RunRecord --> Resume[Resume If Interrupted / Stopped]
   DeploymentValidation --> Diagnostics[Repairable Diagnostics]
 ```
 
+## Workflow API Lifecycle Cohesion
+
+```mermaid
+flowchart LR
+  Context[WorkflowOperationContext] --> API[WorkflowApi]
+  API --> Caps[Capability API]
+  API --> Drafts[Draft API]
+  API --> Artifacts[Artifact API]
+  API --> Deployments[Deployment API]
+  API --> Runs[Run API]
+  Caps --> Specs[WorkflowSpecProvider]
+  Drafts --> DraftStore[Draft Store]
+  Artifacts --> ArtifactStore[Artifact Store]
+  Deployments --> ArtifactStore
+  Runs --> RunStore[Run Store]
+  Runs --> Runtime[WorkflowRuntimeRunner]
+  Runs --> Live[Optional Live Source Checker]
+```
+
 ## Source Provider Boundary
 
 ```mermaid
@@ -97,4 +150,3 @@ flowchart LR
   Inventory --> API[Workflow API Surface]
   API --> Runtime[Workflow Runtime]
 ```
-

docs/add/system-design-implementation.md

@@ -93,11 +93,10 @@ deterministic report-preparation case study backed by a Python source. Section 8
 evaluates the implementation against concrete evidence. Sections 9 and 10
 discuss limitations and future work. Section 11 concludes.
 
-
 # Problem Statement And Requirements
 
-Current agent/tool systems frequently let an LLM directly orchestrate side
+Many direct tool-calling agent patterns let an LLM orchestrate side effects
-effects through ad hoc tool calls. This pattern creates several practical
+through sequential tool calls. This pattern can create several practical
 problems for workspace automation:
 
 - **Weak validation before execution.** A planner that assembles tool-call
@@ -137,15 +136,17 @@ responsibilities of the planner.
 The design requirements that follow from this problem statement are:
 
 1. Typed workflow artifact, deployment, and run lifecycle with explicit schemas.
-2. Source-provider boundary supporting MCP, Python, and future source families.
+2. Source-provider boundary implemented for built-in, MCP, and Python sources,
-3. Durable server, API, and CLI surface that external agents can drive.
+   and designed to admit future source families that can be projected into the
+   existing capability/source contract.
+3. Server, API, and CLI surfaces that external agents can drive, backed by
+   durable lifecycle stores.
 4. Validation and inspection mechanisms intended to reduce planner
    trial-and-error.
 5. Next-action guidance that points an agent toward useful lifecycle operations
    without replacing validation.
 6. Deterministic execution for the thesis-critical evidence path.
 
-
 # Positioning And Related Systems
 
 The system occupies a specific position in the automation landscape. It does
@@ -199,7 +200,6 @@ source-provider correctness matters, because a source may require persistent
 sessions, auth context, catalog refresh, and prompt inventory. The platform
 places this complexity behind a neutral `CapabilitySource` interface.
 
-
 # Conceptual Model
 
 ## Working Glossary
@@ -207,32 +207,45 @@ places this complexity behind a neutral `CapabilitySource` interface.
 The document uses these terms with specific meanings:
 
 | Term | Meaning | Example |
-| --- | --- | --- |
+| --- | ----- | --- |
 | Workflow capability | A workflow-facing callable operation exposed by a source. | `local.report.extract_report` |
-| `NodeSpec` | The typed contract for a capability: input schema, output schema, and outcomes. | a Python `@node` projection |
+| `NodeSpec` | The authoring-layer typed contract produced by decorators or source adapters. | a Python `@node` projection |
+| `NodeDef` | The core-level serializable node contract: input schema, output schema, and declared outcomes. | a workflow plan node definition |
 | Source | A namespace and owner of capabilities, resources, prompts, and metadata. | `local.report`, `wf.std` |
 | Source family | A class of source implementations. | built-in, MCP, Python |
 | Source provider | Server-side code that loads or manages sources for a source family. | Python source loading |
 | Tool | A provider-native operation before projection into workflow form. | MCP tool |
+| Outcome | A control-flow label returned by a node and consumed by graph edges. | `ok`, `error`, `submitted` |
+| Output | The data payload returned by a node or workflow. | `{ "report": "..." }` |
+| Reducer | A pure state-merge operation selected by state schema. | `wf.std.replace`, `wf.std.append` |
+| Platform source | A process-provided source with fixed identity and no deployment binding. | `wf.std`, `wf.source` |
 | Deployment binding | A mapping from logical workflow source requirement to concrete source id. | `local.report=local.report` |
 | Source drift | Divergence between saved workflow requirements and the currently resolved source inventory. | missing capability or changed schema |
 
 ## Workflows as Typed Graphs
 
-A workflow is a typed graph where nodes invoke named capabilities and edges
+A workflow is an outcome-routed typed graph. It is not presented here as a
-route by declared outcomes. The graph model is defined by four schema contracts:
+complete general DAG engine, and it is not a free-form agent state machine.
+Nodes invoke named capabilities; edges route by declared node outcomes. The
+graph model is defined by four schema contracts:
 
 - `input_schema`: validates run input.
 - `state_schema`: defines workflow memory and reducer behavior.
 - `output_schema`: defines the final result shape.
 - Outcome declarations: route control flow through graph edges.
 
-Each node references a `NodeSpec`---a typed contract describing input schema,
+Each node references a core `NodeDef`---a serializable contract describing input
-output schema, and declared outcomes. Reducers merge repeated or otherwise
+schema, output schema, and declared outcomes. Source families commonly produce
-multi-writer state updates safely. General fork/gather parallelism is future
+authoring-layer `NodeSpec`s first; those are projected into `NodeDef` contracts
-work, so this report does not claim complete concurrent graph semantics.
+before the core executes a workflow. The validator checks that routed outcomes
-Interrupts represent typed external input points. Subgraphs compose workflows as
+are declared, that a source node does not have duplicate edges for the same
-nodes.
+outcome, and that reachable outcome edges are present. Reducers merge state
+writes according to state-field declarations. Reducers are pure deterministic
+merge functions invoked by the runtime in workflow execution order; this report
+does not claim CRDT semantics, arbitrary concurrent writes, or order-independent
+aggregation. General fork/gather parallelism is future work, so this report
+does not claim complete concurrent graph semantics. Interrupts represent typed
+external input points. Subgraphs compose workflows as nodes.
 
 The graph model improves the safety posture by making automation structure
 explicit. Node contracts, source requirements, state writes, outcomes,
@@ -274,15 +287,18 @@ execution are distinct operations with distinct lifecycle affordances.
 
 ## Source Model
 
-The common boundary is `CapabilitySource`. The runtime does not care where a
+The common boundary is `CapabilitySource`. Source inventory can expose
-`NodeSpec` came from; source-specific behavior belongs in provider packages and
+provider-derived `NodeSpec`s, reducers, resources, and prompts, but the core
-server composition.
+runtime ultimately executes serialized `NodeDef` contracts and handler
+functions. Source-specific behavior belongs in provider packages and server
+composition.
 
-Four source families exist today:
+Representative sources and source families today:
 
 | Source | Kind | Role |
 | --- | --- | --- |
 | `wf.std` | `system` | Built-in workflow nodes and reducers |
+| `wf.source` | `system` | Built-in source resource helper |
 | `wf.recipes` | `system` | First-party workflow recipes |
 | MCP sources | `connection` | Upstream MCP tools, resources, prompts |
 | Python sources | `python` | Trusted project-local `NodeSpec` registries |
@@ -308,8 +324,9 @@ Python sources.
 
 Source resolution follows a deterministic path: a logical source requirement in
 a workflow is checked against platform sources first, then resolved through
-deployment bindings to concrete sources. The runtime then delegates to the
+deployment bindings to concrete sources. Platform source IDs have fixed runtime
-appropriate source handler.
+identity: deployment validation rejects explicit bindings for platform sources.
+The runtime then delegates to the appropriate source handler.
 
 ## Source Resolution Path
 
@@ -327,7 +344,6 @@ This design allows workflow portability across environments: the same artifact
 can be deployed with different concrete source bindings, while the workflow
 graph references logical names only.
 
-
 # System Architecture
 
 The architecture is organized into layered boundaries, each with a distinct
@@ -353,13 +369,31 @@ flowchart LR
   Sources --> Python[Python Sources]
 ```
 
-The diagram shows the primary flow: a workflow owner expresses intent to an
+The diagram shows the primary flow from workflow owner through agent, CLI,
-external LLM agent, which drives the `wf` CLI. The CLI communicates over
+transport, and server to the API surface, core, platform stores, and source
-JSON-RPC transport to a `WorkflowServer`. The server exposes a Workflow API
+providers. The server composes configured sources into a unified inventory
-Surface that delegates to the deterministic Workflow Core for graph execution and
+without the core runtime being aware of provider-specific details.
-to platform domain objects for artifact, deployment, and run management. Source
+
-providers supply capabilities to the API surface without the core runtime being
+## Layered Package Boundary
-aware of provider-specific details.
+
+Unlike the previous runtime-call diagram, this one maps architectural
+responsibilities onto repository packages. It answers: which package owns each
+boundary in the current implementation?
+
+```mermaid
+flowchart TB
+  CLI[wf_cli] --> Transport[wf_transport_rpc_http]
+  Transport --> Server[wf_server]
+  Server --> API[wf_api]
+  API --> Artifacts[wf_artifacts]
+  API --> Core[wf_core]
+  API --> Platform[wf_platform]
+  Server --> MCP[wf_sources_mcp]
+  Server --> Python[wf_sources_python]
+  MCP --> Platform
+  Python --> Platform
+  Artifacts --> Platform
+```
 
 ## Layer Responsibilities
 
@@ -371,10 +405,13 @@ The layered architecture separates concerns as follows:
 - **Workflow API Surface.** Application operations over capabilities, drafts,
   artifacts, deployments, and runs. The API surface consumes source DTOs through
   a neutral `WorkflowSpecProvider` and delegates to the core for execution.
+  `WorkflowSpecProvider` is the API-facing reader over capability specs derived
+  from source inventory; it is distinct from `WorkflowSourceProvider`, which
+  loads source inventory into the server.
 
-- **Platform Domain.** Draft workspaces, workflow artifacts, deployments, run
+- **Platform Records And Policies.** Draft workspaces, workflow artifacts,
-  records, source inventory snapshots, validation diagnostics, and next-action
+  deployments, run records, source inventory snapshots, validation diagnostics,
-  guidance.
+  and next-action guidance.
 
 - **Server Composition.** `WorkflowServer` assembles concrete stores, sources,
   runtimes, and admin surfaces into a long-lived service. The server composes
@@ -384,9 +421,10 @@ The layered architecture separates concerns as follows:
   The transport is protocol-neutral; the Workflow API Surface is the stable
   boundary.
 
-- **Source Providers.** MCP, Python, and future source families project their
+- **Source Providers.** Built-in, MCP, and Python providers project their
-  inventory into `CapabilitySource` objects. Provider-specific behavior such as
+  inventory into `CapabilitySource` objects. The boundary is designed to admit
-  MCP session pools or Python module loading stays within the provider package.
+  future source families. Provider-specific behavior such as MCP session pools
+  or Python module loading stays within the provider package.
 
 ## Workflow Lifecycle
 
@@ -414,6 +452,8 @@ divergence between saved artifact capability requirements and the currently
 resolved source inventory: missing bindings, missing or disabled sources,
 missing capabilities, or changed schema contracts. Run execution produces
 persisted records with trace slices and resumable stopped state.
+Only interrupted or explicitly stopped runs enter the resume path; completed
+and failed runs remain inspectable records.
 
 ## Workflow Core Model
 
@@ -421,23 +461,60 @@ The core model processes graph execution through typed stages:
 this diagram answers what happens during one run at the graph-execution level.
 
 ```mermaid
-flowchart LR
+flowchart TD
-  Input[Input Schema] --> NodeUse[Node Use]
+  Start[Prepare Run] --> ValidateInput[Validate Workflow Input]
-  NodeSpec[NodeSpec Contract] --> NodeUse
+  ValidateInput --> Select[Select Ready Frame]
-  NodeUse --> Outcome[Declared Outcome]
+  Select --> Step{Step Type}
-  Outcome --> Edge[Graph Edge]
+  Step --> Node[NodeUse]
-  NodeUse --> StateWrite[State Write]
+  Step --> Condition[Condition]
-  StateWrite --> Reducer[Reducer]
+  Step --> Foreach[Foreach]
-  Reducer --> State[Workflow State]
+  Step --> Subgraph[Subgraph]
-  NodeUse --> Trace[Trace Frame]
+  Step --> Interrupt[Interrupt]
-  Interrupt[Interrupt] --> RunState[Stopped Run State]
+  Step --> Join[Join / Minimal Done Step]
-  RunState --> Resume[Resume]
+  Step --> End[End]
+  Node --> ResolveInput[Resolve Input Bindings]
+  ResolveInput --> Handler[Invoke NodeDef Handler]
+  Handler --> CheckOutcome[Check Declared Outcome]
+  CheckOutcome --> StatePatch[Build Reducer-Aware State Patch]
+  StatePatch --> Trace[Append Trace Frame]
+  Condition --> Trace
+  Foreach --> Trace
+  Subgraph --> Trace
+  Join --> Trace
+  Trace --> Route[Route By Outcome Edge]
+  Interrupt --> Stop[Persist Interrupt Request]
+  End --> Finalize[Project Workflow Output]
+  Route --> Select
+  Stop --> Resume[Resume Payload + Outcome]
+  Resume --> Route
 ```
 
-Input validation gates entry. Each node use invokes a `NodeSpec` and produces a
+Input validation gates entry. The runtime then repeatedly selects a ready frame
-declared outcome, a state write, and a trace frame. Outcomes route through graph
+and executes one step. A `NodeUse` resolves input bindings from workflow input,
-edges. Reducers merge state writes safely. Interrupts produce stopped run state
+state, and context; invokes the handler for the selected `NodeDef`; checks that
-that can be resumed.
+the returned outcome is declared; builds reducer-aware state writes; records a
+trace frame; and advances through the edge for that outcome. `Condition`,
+`foreach`, `subgraph`, `join`, `interrupt`, and `end` steps are explicit core
+model variants, not provider-specific hacks. `Join` is currently a minimal step
+that returns a `"done"` outcome; it reserves a graph-level concept for future
+fork/gather semantics.
+
+`foreach` is implemented as an explicit runtime step with frame and lineage
+bookkeeping for iteration and state isolation. This report does not claim a
+general parallel fork/gather model or arbitrary concurrent reducer semantics.
+
+Failure has three visible forms. Structural and dependency failures are
+reported before execution through validation diagnostics. Runtime execution
+failures set the run status to `failed` and store an error string. Business
+failures are modeled as ordinary declared outcomes only when the workflow
+author defines and routes those outcomes.
+
+Interrupts are first-class stop points: an `InterruptNode` builds a typed
+request payload, stores an `InterruptRequest` on the run state, and marks the
+run interrupted. Resume supplies a payload and resume outcome; resume bindings
+write the payload back into state, and routing continues from the declared
+resume outcome. This is resumability at explicit boundaries, not arbitrary
+mid-handler checkpointing.
 
 ## Source Provider Boundary
 
@@ -463,7 +540,6 @@ declared in the workflow config. The server composes all sources into a unified
 `CapabilitySource` inventory that the workflow API surface consumes without
 provider-specific knowledge.
 
-
 # Implementation
 
 ## Package Structure
@@ -473,14 +549,14 @@ The implementation is organized into focused packages with clear boundaries:
 | Package | Responsibility |
 | --- | --- |
 | `wf_core` | Deterministic workflow kernel: graph execution, state, outcomes, trace, resume |
-| `wf_authoring` | Authoring support: `NodeSpec`, drafts, wrappers, API surfaces, source providers |
+| `wf_authoring` | Authoring primitives: `NodeSpec`, `WorkflowBuilder`, DSL, reducer authoring, recipes |
 | `wf_platform` | Neutral source DTOs, source visibility, permissions, and policy |
 | `wf_artifacts` | Artifact, deployment, and run models; file-backed stores; validation |
 | `wf_api` | Application surface: capabilities, drafts, artifacts, deployments, runs |
 | `wf_server` | `WorkflowServer` composition from config, stores, and source providers |
 | `wf_transport_rpc_http` | JSON-RPC over HTTP transport for CLI and future clients |
 | `wf_sources_mcp` | MCP upstream source implementation and persistent runtime pool |
-| `wf_sources_python` | Trusted in-process Python source loading and `NodeSpec` projection |
+| `wf_sources_python` | Trusted in-process Python source loading and `NodeSpec`-to-`NodeDef` projection |
 | `wf_cli` | CLI commands driving the JSON-RPC transport |
 
 (Evidence: `docs/source_architecture.md`, package boundaries in `src/`.)
@@ -490,15 +566,20 @@ The implementation is organized into focused packages with clear boundaries:
 The workflow core implements deterministic execution semantics. It processes a
 typed graph definition, validates input against `input_schema`, executes the
 selected node use, routes by declared outcomes, applies reducers to state
-writes, and produces trace frames. The current public semantics are serial graph
+writes, and produces trace frames. The current public semantics are
-execution with explicit outcomes and interrupts; general fork/gather
+outcome-routed graph execution with explicit condition, foreach, subgraph,
-parallelism is future work. The core is provider-agnostic; it sees `NodeSpec`
+join, interrupt, and end steps. The async runtime has internal frame and lineage
-contracts, not source-specific implementations.
+machinery for foreach admission and state isolation, but this report does not
+claim a complete general fork/gather programming model. The core is
+provider-agnostic; it sees `NodeDef` contracts and handler functions, not
+source-specific implementations.
 
-State writes go through reducers. The platform includes a built-in `wf.std`
+State writes go through reducers. The platform includes built-in `wf.std`
-reducer family. Reducers are themselves `NodeSpec` contracts that can be
+reducer definitions such as `replace`, `append`, `merge_object`, `add`,
-composed into workflows. Interrupts produce stopped run state with a resumable
+`set_union`, and `max`. Reducers are pure merge functions paired with
-checkpoint.
+inspectable `ReducerSpec` metadata; they are exposed in source inventory, but
+they are not ordinary executable node handlers. Interrupts produce stopped run
+state with a resumable checkpoint.
 
 (Evidence: `src/wf_core/`.)
 
@@ -512,9 +593,53 @@ The platform domain defines the lifecycle objects as Pydantic models:
   contract.
 - Run records track execution status, diagnostics, output, and trace counts.
 
-Source binding uses `SourceBinding` objects that map logical source names to
+Source binding uses `SourceBinding` objects defined in `wf_artifacts.models`
-concrete source identifiers. The `CapabilitySource` dataclass is the neutral
+that map logical source names to concrete source identifiers. The
-DTO that all source providers project into.
+`CapabilitySource` dataclass is the neutral DTO that all source providers
+project into.
+
+The lifecycle models are stored in `wf_artifacts`; orchestration of lifecycle
+operations happens one layer above, in `wf_api`.
+
+The API layer holds the lifecycle together rather than acting as thin CRUD over
+files. `WorkflowApi` composes capability, draft, artifact, deployment, and run
+sub-APIs from one `WorkflowOperationContext`. That context carries stores,
+event recording, source inventory, runtime execution, and optional live-source
+checks. This is why CLI, JSON-RPC, and future transports can share the same
+domain operations without importing source-provider internals.
+
+`wf_platform` is intentionally smaller than the API layer. It owns stable
+neutral source vocabulary: `CapabilitySource`, source inventory snapshots,
+declarative visibility and permission metadata, source policy, source refs,
+capability refs, and schema hashes. These flags describe source behavior for
+inventory and validation surfaces; they are not an authorization or
+policy-enforcement layer. `wf_platform` should not grow into a dumping ground
+for stores, runtimes, or provider lifecycle. Those belong in `wf_api`,
+`wf_server`, or the specific `wf_sources_*` package.
+
+The API lifecycle is deliberately centralized through one facade:
+
+```mermaid
+flowchart LR
+  Context[WorkflowOperationContext] --> API[WorkflowApi]
+  API --> Caps[Capability API]
+  API --> Drafts[Draft API]
+  API --> Artifacts[Artifact API]
+  API --> Deployments[Deployment API]
+  API --> Runs[Run API]
+  Caps --> Specs[WorkflowSpecProvider]
+  Drafts --> DraftStore[Draft Store]
+  Artifacts --> ArtifactStore[Artifact Store]
+  Deployments --> ArtifactStore
+  Runs --> RunStore[Run Store]
+  Runs --> Runtime[WorkflowRuntimeRunner]
+  Runs --> Live[Optional Live Source Checker]
+```
+
+The diagram is important because it shows the design contribution at the
+application layer: drafts, artifacts, deployments, and runs are not independent
+file operations. They share source inventory, stores, event recording, runtime
+execution, validation, and live-source checks through one operation context.
 
 (Evidence: `src/wf_artifacts/models.py`, `src/wf_platform/sources.py`.)
 
@@ -534,10 +659,27 @@ severity, error code, logical source reference, repair hint, and the bound
 source. These diagnostics are designed for machine clients: an LLM agent can
 read the diagnostic and determine what to fix without blind probing.
 
+For example, an invalid deployment binding can produce a diagnostic shaped like
+this:
+
+```json
+{
+  "severity": "error",
+  "code": "binding_missing",
+  "logical_ref": "local.report.extract_report",
+  "bound_source": null,
+  "message": "No binding exists for logical source 'local.report'.",
+  "repair_hint": "Bind the logical source to a compatible concrete source."
+}
+```
+
 Deployment validation also detects source drift. If a source changes
 incompatibly and a deployment becomes unrunnable, the system reports the
 diagnostic with a repair hint rather than silently executing against
-incompatible capabilities.
+incompatible capabilities. In this prototype, schema drift is detected through
+saved required-capability schema hashes compared with current source inventory
+hashes when both sides provide hashes; it does not attempt semantic
+backward-compatibility analysis.
 
 (Evidence: `src/wf_artifacts/validation.py`, `tests/artifacts/test_validation.py`.)
 
@@ -548,10 +690,11 @@ object tells a machine client whether there is an obvious next workflow-surface
 tool call, what that tool is, and why. It is guidance, not authority: validation
 diagnostics and runtime status remain the source of truth.
 
-The `NextActions` object includes `can_continue`, `recommended_next_tool`,
+The `NextActions` object includes `can_continue`, `can_save_now`,
-`reason`, and `patch_examples` with concrete request payloads. This makes the
+`recommended_next_tool`, `reason`, `patch_examples` with concrete request
-surface agent-operable: an LLM agent can read the hint and execute the suggested
+payloads, and `warnings`. This makes the surface agent-operable: an LLM agent
-operation without reconstructing the lifecycle state.
+can read the hint and execute the suggested operation without reconstructing
+the lifecycle state.
 
 (Evidence: `src/wf_api/next_actions.py`.)
 
@@ -563,8 +706,9 @@ does not own workflow semantics; it delegates to `WorkflowApi` for application
 operations.
 
 The config model specifies store configuration, transport endpoints, and source
-provider declarations. Sources are declared as discriminated unions by kind:
+provider declarations. The current config model includes implemented source
-`mcp`, `python`, or future kinds like `openapi`.
+kinds such as `mcp` and `python`; future kinds such as `openapi` would extend
+the same discriminated-union pattern.
 
 (Evidence: `src/wf_server/config.py`.)
 
@@ -597,11 +741,11 @@ The MCP source provider manages:
 - A persistent session pool for stateful upstream operations.
 - MCP-to-workflow converters for tools, resources, and prompts.
 
-The provider projects MCP tools into `NodeSpec` contracts, making them callable
+The provider projects MCP tools into `NodeSpec` contracts and corresponding
-from workflow graphs through the same `CapabilitySource` boundary as Python or
+core `NodeDef` contracts, making them callable from workflow graphs through the
-built-in sources.
+same `CapabilitySource` boundary as Python or built-in sources.
 
-(Evidence: `src/wf_sources_mcp/`, `tests/wf_sources_mcp/test_runtime.py`,
+(Evidence: `src/wf_sources_mcp/`, `tests/wf_sources_mcp/test_runtime.py`,  
 `tests/wf_transport_rpc_http/test_mcp_backed_server_rpc.py`.)
 
 ## Python Source Provider
@@ -617,17 +761,19 @@ PythonSourceConfig(path, module, registry)
   -> PythonSourceProvider
   -> import module
   -> load NodeSpec registry
+  -> project specs into NodeDef contracts
   -> qualify specs under source id
   -> CapabilitySource(kind="python")
 ```
 
 Python sources are static at server startup. No hot reload is implemented yet.
 The provider imports the configured module, reads the named registry attribute,
-and projects each `NodeSpec` into the workflow capability inventory.
+projects each `NodeSpec` into the workflow capability inventory, and makes the
+corresponding `NodeDef` contract available to workflow plans. This keeps the
+core provider-agnostic.
 
 (Evidence: `src/wf_sources_python/`, `tests/wf_sources_python/test_loader.py`.)
 
-
 # Case Study: Deterministic Report Workflow
 
 The thesis case study is a document/report preparation workflow backed by local
@@ -637,6 +783,11 @@ artifact saving, deployment validation, run execution, run inspection, and
 trace viewing. The case study is deterministic and does not require an LLM
 call, remote OAuth, or provider quota.
 
+This case study evaluates lifecycle integration rather than graph
+expressiveness. Graph features such as interrupts, foreach, subgraphs, joins,
+and reducer behavior are covered by targeted tests and code evidence in the
+evaluation section.
+
 ## Case Study Components
 
 The example bundle lives at
@@ -775,8 +926,13 @@ programmatically:
    bindings, starts a run, and asserts that the run completes with the expected
    typed output.
 
-(Evidence: `tests/examples/test_report_workflow_example.py`.)
+The thesis-critical run path therefore demonstrates the full lifecycle using a
+single deterministic extraction node. The surrounding Python source includes
+additional capabilities used for capability discovery and extensibility
+evidence; it is not evaluated as a multi-node read -> extract -> render
+pipeline in this artifact.
 
+(Evidence: `tests/examples/test_report_workflow_example.py`.)
 
 # Evaluation
 
@@ -791,7 +947,8 @@ The evaluation is organized around criteria derived from the research question:
 | Criterion | Question | Evidence Type |
 | --- | --- | --- |
 | Representation | Can workflow intent be represented as artifacts, deployments, and runs? | model/API tests |
-| Validation | Can invalid drafts, deployments, source bindings, and source drift be reported before or during execution? | validation/diagnostic tests |
+| Validation | Can invalid drafts, deployments, source bindings, and source drift be reported before execution? | validation/diagnostic tests |
+| Runtime observability | Can runtime failures be persisted as failed run records with inspectable error state? | run API tests |
 | Execution | Can a deterministic workflow execute through the same API/CLI lifecycle used by agents? | report-workflow case study |
 | Persistence | Are lifecycle records persisted, and can stopped/interrupted runs resume at defined boundaries? | run-store and resume tests |
 | Source extensibility | Can different source families expose capabilities without changing `wf_core`? | built-in, MCP, and Python source tests |
@@ -819,6 +976,16 @@ the prototype outperforms mature automation products.
 
 The evidence supporting the thesis claims includes:
 
+| Claim | Evidence | What it asserts | Result |
+| --- | --- | --- | --- |
+| Deployment validation catches source drift | `tests/artifacts/test_validation.py` | Missing, disabled, or changed capabilities produce diagnostics | Pass in focused test suite |
+| Interrupted runs resume at explicit boundaries | `tests/wf_api/test_run_api.py` and resume-concurrency tests | Stopped run state is persisted and resumed through the run API | Pass in focused test suite |
+| Python source lifecycle works | `tests/examples/test_report_workflow_example.py` | Python capability -> artifact -> deployment -> run completes | Pass in focused test suite |
+| CLI and JSON-RPC share the API surface | `tests/wf_transport_rpc_http/` and `tests/wf_cli/` | Transport and CLI delegate to the same workflow operations | Pass in focused test suite |
+
+The table summarizes repository evidence; it is not a substitute for rerunning
+the verification commands before final submission.
+
 ### Architecture And Code Walkthrough
 
 The four-layer architecture (core, API surface, server composition, transport)
@@ -861,7 +1028,7 @@ workflow calls rather than creating fresh one-off clients. This demonstrates
 source-provider correctness for providers whose behavior depends on session
 state.
 
-(Evidence: `tests/wf_sources_mcp/test_runtime.py`,
+(Evidence: `tests/wf_sources_mcp/test_runtime.py`,  
 `tests/wf_transport_rpc_http/test_mcp_backed_server_rpc.py`.)
 
 ### Python Source Case Study
@@ -884,8 +1051,8 @@ machine-readable responses.
 ### Config Validation
 
 Config validation catches import and path errors before server startup. This
-prevents the server from starting with broken source configurations, reducing
+prevents the server from starting with broken source configurations and
-blind agent retries.
+provides earlier, structured failure feedback.
 
 (Evidence: `src/wf_config/`.)
 
@@ -954,7 +1121,6 @@ The implementation addresses these evaluation questions:
    deployment validation reports unrunnable state with diagnostics instead of
    silently executing against incompatible capabilities.
 
-
 # Limitations
 
 The following limitations are stated explicitly to maintain credibility and
@@ -1017,7 +1183,6 @@ deployment concerns beyond the controlled system-design evidence in this report.
 - **No approval, roles, policy, or multi-user review.** There is no
   role-based access control or review workflow.
 
-
 # Future Work
 
 The following areas are identified as likely future work:
@@ -1058,7 +1223,6 @@ The following areas are identified as likely future work:
   benchmarks, and broader agent evaluation with more attempts and failure
   categories.
 
-
 # Conclusion
 
 External LLM agents can author and operate workflows, but reusable workflow
@@ -1071,8 +1235,10 @@ The implementation supports five claims:
 
 1. A typed artifact, deployment, and run lifecycle provides persisted workflow
    records and resumability at explicit stopped/interrupted boundaries.
-2. The source-provider boundary allows MCP, Python, and future source families
+2. The source-provider boundary lets built-in, MCP, and Python sources share
-   to share one workflow surface without core-runtime changes.
+   one workflow surface, and is designed to admit future source families that
+   can be projected into the existing capability/source contract without
+   core-runtime changes.
 3. Validation and diagnostics produce machine-readable repairable failure
    states intended to reduce planner trial-and-error.
 4. The CLI and JSON-RPC transport provide an agent-operable surface that
@@ -1086,7 +1252,6 @@ demonstrates the architecture; the thesis contribution is the platform design
 and evidence that the design can work across multiple source families under
 controlled conditions.
 
-
 # Appendices
 
 ## Appendix A: Case Study Command Transcript
@@ -1115,49 +1280,63 @@ uv run wf --config examples/report_workflow/wf.config.json status
 ### Capability Discovery
 
 ```powershell
-uv run wf --config examples/report_workflow/wf.config.json cap list --source local.report
+uv run wf --config examples/report_workflow/wf.config.json `
+ cap list --source local.report
 ```
 
 ### Capability Call
 
 ```powershell
-uv run wf --config examples/report_workflow/wf.config.json cap call local.report.extract_report --input-file examples/report_workflow/cap-input.json --format compact
+uv run wf --config examples/report_workflow/wf.config.json `
+cap call local.report.extract_report `
+--input-file examples/report_workflow/cap-input.json --format compact
 ```
 
 ### Draft Creation
 
 ```powershell
-uv run wf --config examples/report_workflow/wf.config.json draft create-from-capability report_ws local.report.extract_report --name report_case_study --title "Report Case Study"
+uv run wf --config examples/report_workflow/wf.config.json `
+draft create-from-capability report_ws local.report.extract_report `
+ --name report_case_study --title "Report Case Study"
 ```
 
 ### Draft Validation
 
 ```powershell
-uv run wf --config examples/report_workflow/wf.config.json draft validate report_ws
+uv run wf --config examples/report_workflow/wf.config.json `
+draft validate report_ws
 ```
 
 ### Artifact Saving
 
 ```powershell
-uv run wf --config examples/report_workflow/wf.config.json draft save report_ws --artifact report_case_study --version 1 --title "Report Case Study" --binding local.report=local.report
+uv run wf --config examples/report_workflow/wf.config.json `
+draft save report_ws --artifact report_case_study --version 1 `
+--title "Report Case Study" --binding local.report=local.report
 ```
 
 ### Deployment Saving
 
 ```powershell
-uv run wf --config examples/report_workflow/wf.config.json deploy save report_case_study.default --artifact report_case_study --version 1 --binding local.report=local.report
+uv run wf --config examples/report_workflow/wf.config.json `
+deploy save report_case_study.default --artifact report_case_study `
+--version 1 --binding local.report=local.report
 ```
 
 ### Deployment Validation
 
 ```powershell
-uv run wf --config examples/report_workflow/wf.config.json deploy validate report_case_study.default
+uv run wf --config examples/report_workflow/wf.config.json `
+deploy validate report_case_study.default
 ```
 
 ### Run Execution
 
 ```powershell
-uv run wf --config examples/report_workflow/wf.config.json run start report_case_study.default --input-file examples/report_workflow/run-input.json --trace-from 0 --trace-limit 5
+uv run wf --config examples/report_workflow/wf.config.json `
+run start report_case_study.default `
+--input-file examples/report_workflow/run-input.json `
+--trace-from 0 --trace-limit 5
 ```
 
 ### Run Inspection
@@ -1170,7 +1349,8 @@ uv run wf --config examples/report_workflow/wf.config.json run inspect <run_id>
 ### Run Trace
 
 ```powershell
-uv run wf --config examples/report_workflow/wf.config.json run trace <run_id> --from 0 --limit 5
+uv run wf --config examples/report_workflow/wf.config.json `
+run trace <run_id> --from 0 --limit 5
 ```
 
 ## Appendix B: Evidence Index
@@ -1178,7 +1358,7 @@ uv run wf --config examples/report_workflow/wf.config.json run trace <run_id> --
 See [evidence-index.md](evidence-index.md) for the full claim-to-evidence map.
 
 | Claim | Evidence |
-| --- | --- |
+| --- | ----- |
 | Workflow lifecycle models | `src/wf_artifacts/models.py`, `src/wf_artifacts/runs/` |
 | Source provider boundary | `src/wf_platform/sources.py`, `src/wf_server/config.py` |
 | JSON-RPC/CLI surface | `src/wf_transport_rpc_http/`, `src/wf_cli/` |