feat: add governance system for prompt evolution

Implement a comprehensive governance system to manage agent prompt changes safely.

Key features:
- **Proposal Workflow:** Prompt changes are now "proposals" stored in `src/proposals/` with metadata and diffs.
- **Governance Agent:** A new `governance-agent` reviews and applies proposals using `scripts/governance/process-proposals.mjs`.
- **Validation:** Strict validation ensures changes are limited to allowed directories (`src/prompts/daily|weekly`) and preserve required headers.
- **Lock Enhancements:** Lock events now include `promptHash`, `promptPath`, and `gitCommit` for full auditability.
- **Rollback:** New `torch-lock rollback` command restores prompts from local history (`.torch/prompt-history/`) or git.
- **CLI:** Added `proposal` (create, list, show, apply, reject) and `rollback` commands.

This establishes a "Stage -> Evaluate -> Apply" gate for prompt evolution, preventing silent drift and ensuring constitutional stability.

Co-authored-by: PR0M3TH3AN <[email protected]>

scripts/governance/process-proposals.mjs

@@ -0,0 +1,45 @@
+import { listProposals, applyProposal, rejectProposal, validateProposal } from '../../src/services/governance/index.js';
+
+async function main() {
+  console.log('Governance: Scanning for pending proposals...');
+  const proposals = await listProposals();
+  const pending = proposals.filter(p => p.status === 'pending');
+
+  if (pending.length === 0) {
+    console.log('No pending proposals found.');
+    return;
+  }
+
+  console.log(`Found ${pending.length} pending proposals.`);
+
+  for (const p of pending) {
+    console.log(`\nProcessing proposal: ${p.id} (Target: ${p.target})`);
+
+    // 1. Validate
+    const validation = await validateProposal(p.id);
+    if (!validation.valid) {
+      console.error(`  Validation FAILED: ${validation.reason}`);
+      await rejectProposal(p.id, validation.reason);
+      console.log(`  Rejected proposal ${p.id}.`);
+      continue;
+    }
+    console.log('  Validation PASSED.');
+
+    // 2. Apply
+    try {
+      await applyProposal(p.id);
+      console.log(`  Applied proposal ${p.id} successfully.`);
+    } catch (e) {
+      console.error(`  Application FAILED: ${e.message}`);
+      // Maybe reject with application error?
+      await rejectProposal(p.id, `Application failed: ${e.message}`);
+    }
+  }
+
+  console.log('\nGovernance cycle complete.');
+}
+
+main().catch(err => {
+  console.error('Fatal error in governance script:', err);
+  process.exit(1);
+});