feat: add draft step capability helper

skills/wf-workflow/references/draft-workspaces.md

@@ -75,6 +75,7 @@ Prefer focused helpers over JSON Patch for common edits:
 - `set_step_output_map`
 - `add_state_schema_from_output`
 - `bind_output_to_state`
+- `add_step_from_capability`
 
 CLI equivalents:
 
@@ -87,6 +88,7 @@ wf draft set-output <workspace_id> --revision <n> --step <step_id> --map text=st
 wf draft set-output <workspace_id> --revision <n> --step <step_id> --merge --map other=state.other
 wf draft add-state-from-output <workspace_id> --revision <n> --step <step_id> --output <field> --state state.<field>
 wf draft bind-output-to-state <workspace_id> --revision <n> --step <step_id> --output <field> --state state.<field>
+wf draft add-step-from-capability <workspace_id> --revision <n> --step <step_id> --capability <qualified_name> --from-step <prev> --from-outcome ok --outcome ok --to <next-or-__end__> --input input.text=text --bind-output result=state.result
 ```
 
 `set-input` direction: `input.text=text` means graph source `input.text` maps to
@@ -118,6 +120,19 @@ wf draft bind-output-to-state <workspace_id> --revision <n> --step <step_id> --o
 wf draft validate <workspace_id>
 ```
 
+- `add_step_from_capability`
+
+  Adds a new capability-backed step with explicit route, input bindings, and
+  output-to-state schema/binding wiring in one revision. It can set the incoming
+  edge, outgoing edge, input map, and output-to-state schema/binding. It still
+  requires explicit choices; if you do not know a map, inspect the capability or
+  run validation rather than guessing.
+
+```bash
+wf draft add-step-from-capability <workspace_id> --revision <n> --step <step_id> --capability <qualified_name> --from-step <prev> --from-outcome ok --outcome ok --to <next-or-__end__> --input input.text=text --bind-output result=state.result
+wf draft validate <workspace_id>
+```
+
 Validation repair hints are product guidance. If a diagnostic suggests
 `bind-output-to-state`, use it before hand-editing `state_schema` or step output
 bindings.

skills/wf-workflow/references/workflow-lifecycle.md

@@ -23,6 +23,13 @@ validated, runnable deployment.
    - Use `bind-output-to-state` when a capability output should become state;
      it declares the matching state schema and merges the output binding in one
      revision-checked edit.
+   - When adding a new capability-backed step, prefer:
+     ```bash
+     wf draft add-step-from-capability ...
+     wf draft validate <workspace_id>
+     ```
+     Use raw `wf draft patch` only when changing structure that no focused helper
+     covers.
    - Use JSON Patch only for general structural edits.
 6. Save an artifact.
    - Draft artifact: