fix(taskctl): Pulse not detecting commits in worktrees causing adversarial never to spawn

[randomm]

Critical Bug

Pulse fails to detect commits in worktrees, causing adversarial-developer to never spawn. Pipeline hangs in "reviewing" forever with infinite developer respawns.

Correct Workflow (Verified by Code Analysis)

Intended flow:

1. Developer writes code → commits in worktree (git add -A && git commit)
2. Developer session ends → Pulse heartbeat detects this → Task transitions to "reviewing"
3. Pulse schedules adversarial → checks hasCommittedChanges() → If true, spawn adversarial
4. Adversarial reviews committed work → Records verdict via taskctl verdict
5. If APPROVED → @ops commits and pushes
6. If ISSUES_FOUND → Respawn developer for fixes

Evidence from code:

• developer-pipeline.txt:17 - ✅ git add + git commit in your worktree
• developer-pipeline.txt:51 - When all checks pass: commit your changes
• pulse-utils.ts:53 - git diff ${base_commit}..HEAD --stat (checks COMMITTED changes)
• pulse-scheduler.ts:349 - hasChanges = await hasCommittedChanges(...) (must be true to spawn adversarial)

Bug: hasCommittedChanges Not Detecting Commits

Symptoms:

• Developer commits work (verified by git log in worktree)
• Pulse reports: "No committed changes found. Developer wrote code but did not commit."
• Adversarial never spawns → Pipeline stuck forever

Root Cause (Per Investigation):

spawnDeveloper in pulse-scheduler.ts:177 calculates base_commit incorrectly:

const res = await $`git merge-base ${base} HEAD`.cwd(worktreeInfo.directory)

Problem: HEAD in a worktree is relative to that worktree's current state, which may not align with how hasCommittedChanges checks for commits.

Evidence:

• Worktree has commit 9c13ebf21 (verified by git log)
• hasCommittedChanges returns false despite commits existing
• Base commit calculation is wrong for worktrees

Fix Required

1. Base commit calculation: Use worktree branch name instead of HEAD for merge-base:

   const res = await $`git merge-base ${base} ${worktreeInfo.branch}`.cwd(worktreeInfo.directory)

2. Alternative: Check for uncommitted changes instead:

   • git diff --cached for staged changes
   • git diff HEAD for all changes (committed + staged)
   • git log -1 to check if any commits exist since branch creation

Files Affected

• packages/opencode/src/tasks/pulse-utils.ts - hasCommittedChanges (line 43-61)
• packages/opencode/src/tasks/pulse-scheduler.ts - spawnDeveloper base_commit calculation (line 174-201)

Quality Gates

• Test: hasCommittedChanges returns true for committed work in worktree
• Test: Adversarial spawns after developer commits
• End-to-end: Run taskctl pipeline and verify adversarial spawns

Acceptance Criteria

• Pulse detects commits correctly in worktrees
• Adversarial spawns after developer commits
• No false "No committed changes found" messages
• Pipeline progresses: developing → reviewing → adversarial-running → done

[randomm]

Closing: fixed in #404