chore: configure dual-mode AI code review (#1511)

Add Augment Code Review (audit mode) and CodeRabbit (adversarial mode):

Augment (.augment/code_review_guidelines.yaml):
- Workflow structure and step validation rules
- Agent definition validation
- Path placeholder enforcement
- JIT loading and HALT requirements

CodeRabbit (.coderabbit.yaml):
- Raven-style adversarial reviewer persona
- Finds logical contradictions and missing implementations
- No rule anchoring - reasons freely

Supporting changes:
- .gitignore: exclude .augment/ from ignore
- eslint.config.mjs: ignore .augment/ directory

fix: clarify .augment gitignore pattern and eslint comment

Add documentation comment to .gitignore explaining the .augment/*
exception pattern, and replace misleading eslint comment about
"underscores per their spec" with accurate description of vendor
config directory exclusion.

Addresses CodeRabbit findings F10 and F11 from PR #1511 review.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

fix: remove redundant eslint ignore patterns

The broader glob patterns (dir/**) already match all files recursively,
making the more specific sub-patterns (dir/**/*.js, dir/**/*.md, etc.)
completely redundant. Similarly, _bmad*/** already covers _bmad/**.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

fix: synchronize ignore baselines across CodeRabbit and Augment configs

Expand path exclusions in both PR review tools to a shared baseline:
- Mutual config exclusions (each tool ignores its own and others configs)
- Build output, vendored/generated files, package metadata, binary/media
- Test fixtures, non-project dirs, AI assistant dirs, build temp
- Generated reports

CodeRabbit goes from 1 exclusion to 32; Augment from 12 to 32.
ESLint already had comprehensive ignores and is unchanged.

Addresses CodeRabbit findings F2 and F4 from PR #1511 review.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

fix: correct project name in Augment review guidelines

fix: remove instruction that explicitly encourages false positives

.coderabbit.yaml

@@ -17,21 +17,66 @@ reviews:
     base_branches:
       - main
   path_filters:
+    # --- Shared baseline: tool configs ---
+    - "!.coderabbit.yaml"
+    - "!.augment/**"
+    - "!eslint.config.mjs"
+    # --- Shared baseline: build output ---
+    - "!dist/**"
+    - "!build/**"
+    - "!coverage/**"
+    # --- Shared baseline: vendored/generated ---
     - "!**/node_modules/**"
+    - "!**/*.min.js"
+    - "!**/*.generated.*"
+    - "!**/*.bundle.md"
+    # --- Shared baseline: package metadata ---
+    - "!package-lock.json"
+    # --- Shared baseline: binary/media ---
+    - "!*.png"
+    - "!*.jpg"
+    - "!*.svg"
+    # --- Shared baseline: test fixtures ---
+    - "!test/fixtures/**"
+    - "!test/template-test-generator/**"
+    - "!tools/template-test-generator/test-scenarios/**"
+    # --- Shared baseline: non-project dirs ---
+    - "!_bmad*/**"
+    - "!website/**"
+    - "!z*/**"
+    - "!sample-project/**"
+    - "!test-project-install/**"
+    # --- Shared baseline: AI assistant dirs ---
+    - "!.claude/**"
+    - "!.codex/**"
+    - "!.agent/**"
+    - "!.agentvibes/**"
+    - "!.kiro/**"
+    - "!.roo/**"
+    - "!.github/chatmodes/**"
+    # --- Shared baseline: build temp ---
+    - "!.bundler-temp/**"
+    # --- Shared baseline: generated reports ---
+    - "!**/validation-report-*.md"
+    - "!CHANGELOG.md"
   path_instructions:
     - path: "**/*"
       instructions: |
-        Focus on inconsistencies, contradictions, edge cases and serious issues.
-        Avoid commenting on minor issues such as linting, formatting and style issues.
-        When providing code suggestions, use GitHub's suggestion format:
-        ```suggestion
-        <code changes>
-        ```
-    - path: "**/*.js"
-      instructions: |
-        CLI tooling code. Check for: missing error handling on fs operations,
-        path.join vs string concatenation, proper cleanup in error paths.
-        Flag any process.exit() without error message.
+        You are a cynical, jaded reviewer with zero patience for sloppy work.
+        This PR was submitted by a clueless weasel and you expect to find problems.
+        Be skeptical of everything.
+        Look for what's missing, not just what's wrong.
+        Use a precise, professional tone — no profanity or personal attacks.
+
+        Review with extreme skepticism — assume problems exist.
+        Find at least 10 issues to fix or improve.
+
+        Do NOT:
+        - Comment on formatting, linting, or style
+        - Give "looks good" passes
+        - Anchor on any specific ruleset — reason freely
+
+        If you find zero issues, re-analyze — this is suspicious.
 chat:
   auto_reply: true # Response to mentions in comments, a la @coderabbit review
 issue_enrichment: