docs(coordination): architecture-review kickoff prompts + followup planning

Adds the four kickoff prompts that drove the 2026-05-04 whole-codebase
architecture audit (PM + DEV-A/B/C reviewers), the planning prompt
that converts the synthesis into three implementation plans, and the
PM + DEV-A/B/C kickoff prompts for executing those plans in parallel.

Also updates the existing v0.5.1-* prompts with the relay-server
fallback section that references the new tools/relay/call.py shim.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

docs/superpowers/coordination/v0.5.1-dev-a-prompt.md

@@ -69,8 +69,22 @@ Your vault.ts should call `renderSettings(pane)` when the `#settings` route is a
 - `glyphs.ts` is the single source of truth. No inline Unicode literals at call sites.
 - Don't merge to main. The PM owns merges.
 
+## Relay server
+
+A message-bus MCP server is running on `localhost:7331`. You have three native tools:
+
+- `post_message(from, to, kind, body)` — push a message; your `from` is always `"dev-a"`
+- `read_messages(for)` — drain your inbox; call with `for="dev-a"` before each task
+- `list_pending(for)` — check inbox count without consuming
+
+Recipients: `pm`, `dev-a`, `dev-b`, `dev-c`. Use these instead of asking the user to copy-paste. Before starting each task: `read_messages(for="dev-a")`. After emitting any status/question block: `post_message(from="dev-a", to="pm", kind="status"|"question", body="...")`.
+
 ## Coordination protocol
 
+Before starting each task, call `read_messages(for="dev-a")` to drain your inbox.
+
+When posting a status update, call `post_message(from="dev-a", to="pm", kind="status", body="...")` with the body:
+
 ```
 ## STATUS UPDATE — DEV-A
 Time: <iso8601>
@@ -1438,6 +1452,8 @@ gh pr create --title "feat: fullscreen 3-column layout + popup polish (Stream A)
 
 - [ ] **Step 5: Post status to PM**
 
+Call `post_message(from="dev-a", to="pm", kind="status", body="...")` with:
+
 ```
 ## STATUS UPDATE — DEV-A
 Time: <iso8601>