feat(register): modular @-import CLAUDE.md structure (ops-bridge pattern)

Replaces the monolithic project_claude_md.template with a directory of
7 focused rule files in scripts/project_rules/. register_project.sh now
generates .claude/rules/*.md + a thin CLAUDE.md index of @-imports,
matching the pattern established in ops-bridge.

Template files:
  claude-md.template          — 9-line @-import index
  repo-identity.template      — purpose, domain, slug, topic ID (machine-gen)
  session-protocol.template   — orient/inbox/workplans/brief/close (machine-gen)
  first-session.template      — bootstrap flow; delete once past FSP
  workplan-convention.template— prefix, location; delegates to global CLAUDE.md
  stack-and-commands.template — language/deps/commands (stub, manual)
  architecture.template       — design overview (stub, manual)
  repo-boundary.template      — what this repo does NOT own (stub, manual)

register_project.sh changes:
  - Generates .claude/rules/ from templates with variable substitution
  - Writes thin CLAUDE.md if none exists; appends suggestion comment if one does
  - Step 7: auto-registers this machine's local path via POST /repos/{slug}/paths/
  - project_claude_md.template deprecated to a redirect notice

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

scripts/project_rules/first-session.template

@@ -0,0 +1,38 @@
+## First Session Protocol
+
+Triggered when `get_domain_summary("{DOMAIN}")` shows **no workstreams**.
+The project is registered but work has not yet been structured.
+
+**Step 1 — Read, don't write**
+- `~/the-custodian/canon/projects/{DOMAIN}/project_charter_v0.1.md` — purpose, scope
+- `~/the-custodian/canon/projects/{DOMAIN}/roadmap_v0.1.md` — planned phases
+- Scan repo root: README, directory structure, existing code or docs
+
+**Step 2 — Survey in-progress work**
+Look for TODOs, open branches, half-finished files. Note done vs. started but incomplete.
+
+**Step 3 — Propose workstreams to Bernd**
+Propose 1–3 workstreams — each a coherent strand, weeks to months, anchored to a
+roadmap phase. **Wait for approval before creating.**
+
+**Step 4 — Create workplan file first, then DB record (ADR-001)**
+```
+workplans/{REPO_SLUG}-WP-NNNN-<slug>.md   ← write this first
+```
+Then register in the hub:
+```
+create_workstream(topic_id="{TOPIC_ID}", title="...", owner="...", description="...")
+create_task(workstream_id="<id>", title="...", priority="high|medium|low")
+```
+
+**Step 5 — Record the setup**
+```
+add_progress_event(
+    summary="First session: structured {DOMAIN} into N workstreams, M tasks",
+    event_type="milestone",
+    topic_id="{TOPIC_ID}",
+    detail={"workstreams": [...], "tasks_created": M}
+)
+```
+
+<!-- Delete or archive this file once past first session -->