docs: agent worktree-flow documentation + CLAUDE.md

README: updated wait_for_job/update_job_status tool descriptions,
added 'Agent worktree-flow' section with env vars, config-file fallback,
and smoke-test checklist. New CLAUDE.md with worktree-flow summary and
key source file index.

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

CLAUDE.md

@@ -0,0 +1,56 @@
+# CLAUDE.md — scrum4me-mcp
+
+MCP server that exposes the Scrum4Me dev-flow as native tools for Claude Code.
+
+## Agent worktree-flow
+
+`wait_for_job` creates an isolated git worktree per job so agent changes never touch the user's main checkout.
+
+### How it works
+
+1. On successful claim, `wait_for_job` calls `createWorktreeForJob`:
+   - Worktree directory: `SCRUM4ME_AGENT_WORKTREE_DIR/<job-id>` (default: `~/.scrum4me-agent-worktrees/<job-id>`)
+   - Branch: `feat/job-<last-8-chars-of-job-id>` (timestamp-suffixed if branch already exists)
+   - Base: `origin/main`
+2. Tool response includes `worktree_path` and `branch_name`.
+3. **Work exclusively in `worktree_path`** — all file edits and commits go there.
+4. On `update_job_status(done|failed)`, `removeWorktreeForJob` runs automatically:
+   - `keepBranch=true` if `done` and a `branch` was reported (agent pushed)
+   - `keepBranch=false` otherwise (branch deleted with worktree)
+
+### Required configuration
+
+Set env var per product:
+
+```
+SCRUM4ME_REPO_ROOT_<productId>=/absolute/path/to/local/clone
+```
+
+Or add to `~/.scrum4me-agent-config.json`:
+
+```json
+{
+  "repoRoots": {
+    "<productId>": "/absolute/path/to/local/clone"
+  }
+}
+```
+
+If no repo root is found, `wait_for_job` rolls the claim back to QUEUED and returns an error.
+
+## Key source files
+
+| File | Purpose |
+|---|---|
+| `src/git/worktree.ts` | `createWorktreeForJob` + `removeWorktreeForJob` |
+| `src/tools/wait-for-job.ts` | `resolveRepoRoot`, `rollbackClaim`, `attachWorktreeToJob` |
+| `src/tools/update-job-status.ts` | `cleanupWorktreeForTerminalStatus` |
+
+## Testing
+
+```bash
+npm test          # vitest run
+npm run typecheck # tsc --noEmit
+```
+
+All worktree helpers have unit tests under `__tests__/git/worktree.test.ts`, `__tests__/wait-for-job-worktree.test.ts`, and `__tests__/update-job-status-worktree.test.ts`.