feat: agent authoring & doc generation (WP-0007, v1.4.0)

New authoring tooling and a fix for the doc-regeneration defect it exposed.

Added:
- src/kaizen_agentic/agent_docs.py — render + idempotent upsert of the
  CLAUDE.md "## Installed Agents" section (shared by installer and CLI)
- `kaizen-agentic docs generate [--check]` — idempotent doc refresh / CI gate
- `kaizen-agentic create-agent` — scaffold a schema-valid agent
- Frontmatter schema validation in `kaizen-agentic validate`
  (required name/description/category, known category, valid memory/model)
- tests: test_agent_docs, test_validate_schema, test_create_agent

Fixed:
- _update_documentation regex duplicated the Installed Agents block on every
  run (stopped at the first ### subheading) — now idempotent
- declared frontmatter `category` is authoritative (heuristic is fallback)
- list_installed_agents reads the frontmatter name, not the filename
- renamed agent-project-management.md -> agent-project-assistant.md to satisfy
  the agent-<name>.md convention (eliminates a name/filename collision that
  caused install/update to write a divergent duplicate)
- test_cli_error_handling no longer installs into the repo root (uses tmp)

Version 1.4.0; CHANGELOG, CLI cheat sheet, agency-framework, TODO updated.
Workplan KAIZEN-WP-0007 closed.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

docs/agency-framework.md

@@ -80,6 +80,23 @@ memory: enabled   # or: disabled
 
 The `memory` field defaults to `enabled`. Set `memory: disabled` for agents that are stateless by design (e.g. `wisdom-encouragement`).
 
+The file name must follow `agent-<name>.md` where `<name>` equals the frontmatter
+`name`. `kaizen-agentic validate` enforces the frontmatter schema (required
+fields, known `category`, valid `memory`/`model`).
+
+### Authoring and doc sync (WP-0007)
+
+```bash
+kaizen-agentic create-agent <name> -c <category> -d "<description>"
+kaizen-agentic validate                 # schema + dependency checks
+kaizen-agentic docs generate            # refresh CLAUDE.md Installed Agents
+make agents-sync-package                # keep packaged data/agents/ in parity
+```
+
+`create-agent` writes a schema-valid skeleton; `docs generate` rewrites the
+project `## Installed Agents` section **idempotently** (use `--check` as a CI
+gate). The section is grouped by the declared frontmatter `category`.
+
 ---
 
 ## The Coach Meta-Agent