Configuration in Beads: use pinned beads for rig/agent config

## Summary

Move configuration from JSON files into Beads data plane using pinned beads.

## Motivation

- Config becomes versionable and syncable like issues
- Agents can read config via `bd show`
- Unified data model for everything
- Supports the 'Beads as Universal Data Plane' vision (gt-aqm)

## Config Types to Migrate

### Rig-level (pinned per rig)
- Theme/colors for tmux status line
- Default branch naming conventions
- Merge queue settings
- Witness thresholds

### Agent-level (pinned per role)
- Handoffs (already planned - gt-cu7r)
- Agent preferences
- Current focus/context

### Town-level (pinned at town root)
- Cross-rig settings
- Federation config
- Global themes

## Implementation

1. Implement StatusPinned (beads-6v2) ✓ in progress
2. Create config pinned beads on rig init
3. Add `bd config get/set` commands that read/write pinned beads
4. Migrate existing config.json fields

## Naming Convention

```
<prefix>-cfg-<scope>
gt-cfg-theme      # gastown theme
bd-cfg-merge      # beads merge settings
gm-cfg-town       # town-level config
```

## Dependencies

- beads-6v2: Add StatusPinned to beads schema
- gm-w13: Pinned Beads epic


MVP Cutover: GGT replaces PGT for batch work

When this is closed, stop using town and start using gt.

## Acceptance Criteria

1. gt spawn assigns issue to polecat and starts session
2. gt spawn --epic spawns workers for all epic children
3. gt session manages tmux lifecycle
4. gt send / gt inbox work for mail
5. Refinery processes merge queue with semantic merges
6. Integration branches created and landed correctly
7. gt stop --all halts all sessions
8. One successful test batch completed end-to-end

## What Must Work

- Spawn polecat with issue assignment
- Spawn workers for epic children
- Session start/stop/attach
- Mail send/inbox/read
- Refinery merge loop (semantic)
- Integration branch → main landing
- Witness cleanup protocol
- Emergency stop

## What Can Be Deferred

- Doctor checks (use PGT)
- TUI dashboard
- Plugin system
- Federation
- Ephemeral rigs
- Detailed landing reports

## Test Plan

1. Create epic with 2 tasks, spawn 2 workers
2. Verify polecats get assigned and sessions start
3. Simulate task completion
4. Verify Refinery merges to integration
5. Verify landing to main
6. Verify cleanup

## Validation

Run one real batch implementing GGT issues using GGT.

## Note

No "swarm IDs" - just spawn workers for epic, let merge queue coordinate.


Swarms of One: Lightweight single-worker task dispatch

Design and implement a lightweight pattern for firing off single workers to handle tasks without full swarm overhead.

## Context

Currently we have:
- town spawn: Creates a polecat in a rig with issue assignment
- Swarms (sw-*): Full lifecycle tracking with manifest, state, events, reports
- Ephemeral rigs (rig-*): Temporary worker groups for swarms

What's missing: A simple way to say 'fire off a worker to do X' without swarm ceremony.

## Design Questions

1. Should this be a new command like 'gt fire' or an option on existing commands?
2. Should single tasks still get swarm IDs (sw-N) for consistency/queryability?
3. Should it default to creating new workers or support --reuse for idle polecats?
4. How does this relate to crew workers (gt-cik)?

## Possible Interface

gt fire --rig gastown --issue gt-xyz [--prompt '...']
gt fire gastown/QuickTask --issue gt-xyz

## Related

- gt-cik: Overseer Crew (user-managed persistent workspaces)
- gt-kmn: Swarm System epic


Enhanced polecat decommission prompting

Add decommission checklist to polecat AGENTS.md.template. Make crystal clear: verify ALL before signaling done.

## Checklist for AGENTS.md.template

```markdown
## Decommission Checklist

**CRITICAL**: Before signaling done, you MUST complete this checklist.
The Witness will verify each item and bounce you back if dirty.

### Pre-Done Verification

```bash
# 1. Git status - must be clean
git status
# Expected: "nothing to commit, working tree clean"

# 2. Stash list - must be empty
git stash list
# Expected: (empty output)

# 3. Beads sync - must be up to date
bd sync --status
# Expected: "Up to date" or "Nothing to sync"

# 4. Branch merged - your work must be on main
git log main --oneline -1
git log HEAD --oneline -1
# Expected: Same commit
```

### If Any Check Fails

- **Uncommitted changes**: Commit them or discard if unnecessary
- **Stashes**: Pop and commit, or drop if obsolete
- **Beads out of sync**: Run `bd sync`
- **Branch not merged**: Complete the merge workflow

### Signaling Done

Only after ALL checks pass:

```bash
bd close <issue-id>
bd sync
town mail send <rig>/witness -s "Work Complete" -m "Issue <id> done."
```
```

## Implementation

Add to AGENTS.md.template in the polecat prompting section.


Per-epic config overrides: custom merge settings

Allow per-epic merge configuration overrides.

Epic can specify merge_config in its description:
  merge_config:
    run_tests: true
    test_command: 'go test -race ./...'
    on_conflict: assign_back

When processing MRs for an epic:
1. Load rig-level merge_queue config
2. Check if epic has merge_config
3. Merge epic config over rig config
4. Use merged config for processing

Use cases:
- Risky refactors: more thorough testing
- Urgent fixes: skip some checks
- Experimental work: different test suite

Reference: docs/merge-queue-design.md#per-epic-overrides


Polecats should not bd sync on startup

Polecats all share the same beads database at the rig level. The refinery and mayor/witness manage syncing beads.

## Current Behavior
Polecat startup runs bd sync, causing:
- Contention when multiple polecats spawn simultaneously
- Unnecessary sync operations
- Potential race conditions

## Desired Behavior
- Polecats should NOT run bd sync on startup
- They read from the shared beads database
- Only refinery/witness/mayor sync beads

## Implementation
Remove bd sync from polecat spawn/startup sequence.


Add human escalation configuration

Add overseer contact config to mayor/town.json. Deacon uses this for escalation when it cannot resolve issues. Support email and/or other notification methods.


Tmux status line: rig color themes and worker identity display

## Summary

Customize tmux status line for Gas Town workers with:
1. Per-rig configurable color themes
2. Clear worker name and role visibility

## Current Problem

- Only mayor shows in status line (and truncated)
- Can't tell which rig/worker you're looking at
- All sessions look the same

## Proposed Design

### Per-rig colors
```yaml
# In rig config or beads
theme:
  primary: '#ff6600'    # Orange for gastown
  secondary: '#333333'
  accent: '#ffcc00'
```

### Status line format
```
[gastown/Rictus] polecat | gt-70b3 | branch: polecat/Rictus
[beads/emma] crew | working | branch: main
[mayor] coordinator | idle
```

### Components
- Rig name with rig color
- Worker name
- Role (polecat/crew/mayor/witness/refinery)
- Current issue or status
- Branch name

## Configuration

Could use pinned beads for this (see gm-w13, beads-6v2):
- `bd show <rig>-theme` returns theme config
- Stored as pinned bead, always available
- Part of 'config in beads data plane' initiative

Implementation complete. Core features: per-rig color themes, dynamic status line with issue/mail indicators, gt theme/issue commands. Ready for testing.


Refinery Engineer: Role prompting and CLAUDE.md

Create refinery/CLAUDE.md with Chief Merge Engineer role context. Include:
- Role identity and responsibilities
- Decision authority (merge order, test frequency, binary rebuilds)
- Communication patterns (Witness, Deacon)
- Session lifecycle (handoff bead protocol)
- Key commands reference


Rollback support: gt mq revert for problematic merges

Implement 'gt mq revert <mr-id>' for rolling back merges.

Actions:
1. Find merge commit from closed MR
2. Create revert commit: git revert <merge-commit>
3. Push revert to target branch
4. Create 'reverted' MR tracking the revert
5. Optionally reopen source issue

Options:
- --reason REASON: required explanation
- --reopen-issue: reopen the source work item

Track revert in MR metadata for audit trail.

Reference: docs/merge-queue-design.md#open-questions


Merge: gt-a95

branch: polecat/Ace
target: main
source_issue: gt-a95
rig: gastown


gt handoff: Deadlock in waitForRetirement


Add merge-request type to Beads schema

Define the merge-request bead type with fields:
- branch: source branch (e.g., polecat/Nux/gt-xxx)
- target_branch: destination (main or integration/xxx)
- source_issue: the work being merged (gt-xxx)
- worker: who did the work
- rig: which rig
- merge_commit: (filled on close) SHA of merge commit
- close_reason: (filled on close) success/failure details

This may require beads schema changes or just convention.


CLI: rig commands (list, show, add)

Rig management CLI commands.

## Commands

### gt rig list
List all registered rigs.
```
gt rig list [--json]
```
Output:
- Rig name
- Git URL
- Polecat count
- Witness/Refinery status

### gt rig show
Show details for a specific rig.
```
gt rig show <name> [--json]
```
Output:
- Full rig info
- Polecats with status
- Recent activity
- Beads summary (open issues)

### gt rig add
Add a new rig to the town.
```
gt rig add <name> <git-url>
gt rig add <name> --local <path>
```
Steps:
- Clone repo to town root (or link local)
- Register in rigs.json
- Create agent directories
- Configure git exclude

### gt rig remove
Remove a rig from the town.
```
gt rig remove <name> [--force]
```
- Warns if active polecats
- --force required if uncommitted changes

## Implementation

```go
var rigCmd = &cobra.Command{Use: "rig"}
rigCmd.AddCommand(rigListCmd, rigShowCmd, rigAddCmd, rigRemoveCmd)
```


Work on ga-yp3: Polecat inbox system for reliable work as...

Work on ga-yp3: Polecat inbox system for reliable work assignment. This is P1 priority. See bd show ga-yp3 for full design spec.


Daemon: configurable heartbeat interval

Heartbeat interval is hardcoded to 60s. Should be configurable via:
- town.json config
- Command line flag
- Environment variable

Default 60s is reasonable but some deployments may want faster/slower.


gt park command for parking molecules on external deps

Add `gt park` command for when polecat hits external dependency:

```bash
gt park --step=gt-mol.3 --waiting="beads:mol-run-assignee"
```

This command:
1. Adds blocked_by: external:beads:mol-run-assignee to the step
2. Clears assignee on the step
3. Clears assignee on molecule root
4. Sends handoff mail to self with context
5. Shuts down polecat session

The molecule enters "parked" state (derived: in_progress + no assignee + blocked step).

Part of cross-project dependency system.
See: docs/cross-project-deps.md

Depends on Beads: bd-om4a (external: blocked_by support)