v2.0: state enforcement, project scoping, harness integration

State Enforcement (v2.0):
- .state file as single source of truth for task phase
- Approval gates for research, decomposition, design, test_design
- status.py --transition refuses illegal phase transitions
- status.py --validate-folder detects out-of-order artifacts
- status.py --audit checks all tasks for violations
- status.py --create-task is the only valid way to create tasks
- Pre-v2.0 tasks without .state are UNTRACKED -- all commands refuse them
- New --upgrade command bootstraps .state files for existing tasks

Project Scoping:
- --project flag added to all status.py commands across 16+ files
- _find_project_dir errors instead of silently falling back to ~/.automaton/
- --scope-check marks framework files OUT_OF_SCOPE when working on a project
- Dashboard handlers use stored project_root instead of re-detecting from CWD
- Prompts reference ~/.automaton/scripts/vram_detect.py (not {project}/.automaton/)

Harness Integration:
- status.py --can-edit now supports project-level checks (no --task required)
- --can-edit --file checks file scope without --task
- --json output for machine-readable harness integration
- opencode plugin (plugins/automaton-guard/plugin.ts) intercepts edit/write
- Git pre-commit hook (scripts/git-hooks/pre-commit) blocks commits without task
- Formal integration contract (contracts/harness-integration.md)

Other:
- upgrade.sh delegates to status.py --upgrade instead of manual heuristics
- Phase prompts reference --project {project} for multi-project scoping
- 200 tests passing (14 new)

tasks/multi-agent-support/IMPLEMENTATION.md

@@ -0,0 +1,65 @@
+# Implementation: Multi-Agent Support
+
+## Changes Made
+
+### 1. Agent Configuration in `.agent.md`
+Multi-agent mode is activated by adding an `## Agent Configuration` section to `.agent.md`:
+```markdown
+## Agent Configuration
+Mode: multi-agent
+Agents:
+  - id: researcher
+    phases: [research, decomposition, design, test_design]
+  - id: implementer
+    phases: [implement]
+  - id: orchestrator
+    phases: [new, complete, human_intervention]
+    role: coordinator
+Lock timeout: 30m
+```
+When this section is absent or `Mode: single-agent` (default), all multi-agent commands are no-ops.
+
+### 2. Task claiming: `--claim` and `--release`
+- `status.py --claim --task {name} --agent {id}` creates `.state.lock` with agent ID, phase, claimed timestamp, and expiry
+- Atomic write (`.state.lock.tmp` → `.state.lock`)
+- Refuses if already claimed and not expired
+- Overclaims expired locks with warning
+- Validates agent is configured for the task's current phase
+- Default lock timeout: 30 minutes, configurable in `.agent.md`
+
+### 3. Work discovery: `--next-available` and `--available`
+- `--next-available --agent {id}` returns the highest-priority unclaimed task matching the agent's allowed phases
+- Priority: tasks closest to completion first (referee > doc_review > ... > research > new)
+- `--available --agent {id}` lists all matching tasks
+- In single-agent mode, both return a message directing to `--list`
+
+### 4. Single-agent zero-overhead guarantee
+- When no Agent Configuration exists, `--claim`, `--release`, `--next-available`, `--available` are no-ops or return guidance messages
+- No `.state.lock` files are created in single-agent mode
+- No performance overhead, no behavioral change from v1
+
+### 5. Coordinator role
+- Agent with `role: coordinator` can:
+  - Claim tasks on behalf of other agents (`--claim --agent {target} --as-coordinator`)
+  - Force-release claims (`--release --as-coordinator`)
+  - Force-transition (`--transition {phase} --force`)
+
+### 6. Lock expiry and conflict resolution
+- Locks expire after configurable timeout (default 30 min)
+- Any agent can overclaim expired locks
+- Atomic lock writes prevent race conditions
+- Locks auto-release on `complete` and `human_intervention` transitions
+
+### 7. Role binding in phase prompts
+- When multi-agent mode is active and `--agent` is provided, `status.py --task` includes agent-specific ALLOWED/FORBIDDEN sections
+- Phase prompts include `## Agent Role` section when agent is role-bound
+- `TASK_HANDOFF` signal defined for when agent can't perform a required phase
+
+## Files Modified
+- `scripts/status.py` (multi-agent commands implemented)
+- `tests/test_status.py` (existing tests cover single-agent; multi-agent requires Agent Configuration to test)
+
+## Notes
+- Multi-agent is opt-in: zero config changes needed for single-agent usage
+- The phase prompt `## Agent Role` section is documented in the `multi-agent-support/SPEC.md` but will be dynamically generated by `status.py --task` output when multi-agent is active
+- Dashboard integration for multi-agent status display is future work