feat(skills): Add plan-awareness to bead workflow skills

- parallel_beads: Filter beads by plan readiness before selection
  - Include beads with plans or type=bug
  - Warn about skipped beads that need plans first
- beads_implement: Check for plan based on bead type
  - Bugs can proceed without plans
  - Features/tasks warn and ask user preference
- beads_workflow: Document design decisions
  - Artifacts vs statuses for phase tracking
  - One bead per feature as default
  - Discovered-work pattern for splitting work

Closes: nixos-configs-45r, nixos-configs-8gr, nixos-configs-oog, nixos-configs-505

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

home/roles/development/skills/beads_implement.md

@@ -18,20 +18,49 @@ When this command is invoked:
      ```
      Then check which have plans in `thoughts/beads-{id}/plan.md`
 
-2. **Load bead and plan context**:
+2. **Load bead context**:
    ```bash
    bd show {bead-id}
    ```
+   Note the bead **type** (bug, feature, task) from the output.
+
+3. **Check for plan and handle by type**:
+
+   Check if plan exists:
+   ```bash
+   ls thoughts/beads-{bead-id}/plan.md 2>/dev/null
+   ```
+
+   **If plan exists**: Proceed normally (skip to step 4)
+
+   **If no plan**:
+   - **type=bug**: Proceed without plan (simple bugs can implement directly)
+   - **type=feature or type=task**: Warn and ask:
+     ```
+     No plan found for this {type}.
+
+     Plans help ensure complex work is well-designed and verifiable.
+     Location expected: thoughts/beads-{bead-id}/plan.md
+
+     Options:
+     1. Create a plan first (recommended) - Run /beads_plan {bead-id}
+     2. Proceed without a plan (for simple changes)
+
+     How would you like to proceed?
+     ```
+     Wait for user response before continuing.
+
+4. **Load plan and research context** (if plan exists):
    - Read `thoughts/beads-{bead-id}/plan.md` FULLY
    - Check for any existing checkmarks (- [x]) indicating partial progress
    - Read any research at `thoughts/beads-{bead-id}/research.md`
 
-3. **Mark bead in progress** (if not already):
+5. **Mark bead in progress** (if not already):
    ```bash
    bd update {bead-id} --status=in_progress
    ```
 
-4. **Respond with**:
+6. **Respond with**:
    ```
    Implementing plan for bead {bead-id}: {bead-title}