feat(workflow): auto-route discipline: design to design workflow

Design units no longer require manually setting workflow: design.
Elaborate auto-sets it during unit creation, and construct falls
back to the design workflow when discipline: design is detected.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: jwaldrip

plugin/skills/construct/SKILL.md

@@ -437,11 +437,20 @@ fi
 update_unit_status "$UNIT_FILE" "in_progress"
 ```
 
-3. **Resolve per-unit workflow** — read the unit's `workflow:` frontmatter field. If present, resolve it to a hat sequence. If absent, fall back to the intent-level workflow:
+3. **Resolve per-unit workflow** — read the unit's `workflow:` frontmatter field. If present, resolve it to a hat sequence. If absent, check for discipline-based defaults before falling back to the intent-level workflow:
 
 ```bash
 UNIT_WORKFLOW_NAME=$(han parse yaml workflow -r --default "" < "$UNIT_FILE" 2>/dev/null || echo "")
 
+# Discipline-based fallback: auto-route discipline: design → workflow: design
+if [ -z "$UNIT_WORKFLOW_NAME" ]; then
+  UNIT_DISCIPLINE=$(han parse yaml discipline -r --default "" < "$UNIT_FILE" 2>/dev/null || echo "")
+  case "$UNIT_DISCIPLINE" in
+    design) UNIT_WORKFLOW_NAME="design" ;;
+    *)      ;;  # fall through to intent-level
+  esac
+fi
+
 if [ -n "$UNIT_WORKFLOW_NAME" ]; then
   # Resolve unit-specific workflow
   UNIT_WORKFLOW_HATS=""

plugin/skills/elaborate/SKILL.md

@@ -619,6 +619,8 @@ Do NOT ask the user whether to decompose. Assess the complexity from the domain
 
 Set the `workflow:` frontmatter field on units that need a non-default workflow. Omit it (or leave empty) for units that should use the intent-level workflow.
 
+**Auto-routing rule:** When generating a unit with `discipline: design`, automatically set `workflow: design` in the frontmatter. Do not require the user to specify this manually. This ensures design units always route through the design workflow (`planner → designer → reviewer`) instead of accidentally inheriting the intent-level workflow.
+
 Define each unit with **enough detail that a builder with zero prior context builds the right thing**:
 
 - **Name and description**: What this unit accomplishes, stated in terms of the domain model
@@ -981,7 +983,7 @@ depends_on: []
 branch: ai-dlc/{intent-slug}/NN-{unit-slug}
 discipline: {discipline}  # frontend, backend, api, documentation, devops, design, etc.
 pass: ""  # Which pass this unit belongs to (design, product, dev) — empty for single-pass intents
-workflow: ""  # Per-unit workflow override (optional — omit or leave empty to use intent-level workflow)
+workflow: ""  # Per-unit workflow override (optional — omit or leave empty to use intent-level workflow). Auto-set to "design" when discipline is "design".
 ticket: ""  # Ticketing provider ticket key (auto-populated if ticketing provider configured)
 # git:                         # Optional: per-unit VCS override (only include when unit has an override)
 #   change_strategy: ""        # Overrides intent-level strategy for this unit (e.g., "unit" for foundational units)