feat: [QA][POLICY] Branch Protection + Mandatory Review Policy for All Repos (#918)

Refs #918
Agent: groq

CONTRIBUTING.md

@@ -150,7 +150,44 @@ PRs not updated in >7 days will be labeled "stale" and may be closed after 30 da
 **Every PR: net ≤ 10 added lines.** Not a guideline — a hard limit.
 Add 40, remove 30. Can't remove? You're homebrewing. Import instead.
 
-## Branch Protection Policy
+## Branch Protection & Review Policy
+
+### Branch Protection Rules
+
+All repositories enforce the following rules on the `main` branch:
+
+| Rule | Status | Applies To |
+|------|--------|------------|
+| Require Pull Request for merge | ✅ Enabled | All |
+| Require 1 approval before merge | ✅ Enabled | All |
+| Dismiss stale approvals on new commits | ✅ Enabled | All |
+| Require CI to pass (where CI exists) | ⚠️ Conditional | All |
+| Block force pushes to `main` | ✅ Enabled | All |
+| Block deletion of `main` branch | ✅ Enabled | All |
+
+### Default Reviewer Assignments
+
+| Repository | Required Reviewers |
+|------------|------------------|
+| `hermes-agent` | `@perplexity`, `@Timmy` |
+| `the-nexus` | `@perplexity` |
+| `timmy-home` | `@perplexity` |
+| `timmy-config` | `@perplexity` |
+
+### CI Enforcement Status
+
+| Repository | CI Status |
+|------------|-----------|
+| `hermes-agent` | ✅ Active |
+| `the-nexus` | ⚠️ CI runner pending (#915) |
+| `timmy-home` | ❌ No CI |
+| `timmy-config` | ❌ Limited CI |
+
+### Review Requirements
+
+- All PRs must be reviewed by at least one reviewer
+- `@perplexity` is the default reviewer for all repositories
+- `@Timmy` is a required reviewer for `hermes-agent`
 
 All repositories enforce:
 - ✅ Require Pull Request for merge