feat: Fix-First Review — auto-fix obvious issues, ask about hard ones (v0.4.5) (#116)

* feat: Fix-First Review — auto-fix obvious issues, ask about hard ones

Replace the CRITICAL-only AskUserQuestion flow with Fix-First:
- Every finding gets action (not just critical ones)
- AUTO-FIX items (dead code, N+1, stale comments) applied directly
- ASK items (security, race conditions, design decisions) batched
  into at most one AskUserQuestion
- Fix-First Heuristic in checklist.md (single source of truth)
- Gate Classification → Severity Classification rename

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* chore: bump version and changelog (v0.4.5)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* docs: polish CHANGELOG v0.4.5 voice — lead with user benefit

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

review/checklist.md

@@ -5,21 +5,23 @@
 Review the `git diff origin/main` output for the issues listed below. Be specific — cite `file:line` and suggest fixes. Skip anything that's fine. Only flag real problems.
 
 **Two-pass review:**
-- **Pass 1 (CRITICAL):** Run SQL & Data Safety and LLM Output Trust Boundary first. These can block `/ship`.
-- **Pass 2 (INFORMATIONAL):** Run all remaining categories. These are included in the PR body but do not block.
+- **Pass 1 (CRITICAL):** Run SQL & Data Safety and LLM Output Trust Boundary first. Highest severity.
+- **Pass 2 (INFORMATIONAL):** Run all remaining categories. Lower severity but still actioned.
+
+All findings get action via Fix-First Review: obvious mechanical fixes are applied automatically,
+genuinely ambiguous issues are batched into a single user question.
 
 **Output format:**
 
 ```
 Pre-Landing Review: N issues (X critical, Y informational)
 
-**CRITICAL** (blocking /ship):
-- [file:line] Problem description
-  Fix: suggested fix
+**AUTO-FIXED:**
+- [file:line] Problem → fix applied
 
-**Issues** (non-blocking):
+**NEEDS INPUT:**
 - [file:line] Problem description
-  Fix: suggested fix
+  Recommended fix: suggested fix
 ```
 
 If no issues found: `Pre-Landing Review: No issues found.`
@@ -102,10 +104,10 @@ To do this: use Grep to find all references to the sibling values (e.g., grep fo
 
 ---
 
-## Gate Classification
+## Severity Classification
 
 ```
-CRITICAL (blocks /ship):          INFORMATIONAL (in PR body):
+CRITICAL (highest severity):      INFORMATIONAL (lower severity):
 ├─ SQL & Data Safety              ├─ Conditional Side Effects
 ├─ Race Conditions & Concurrency  ├─ Magic Numbers & String Coupling
 ├─ LLM Output Trust Boundary      ├─ Dead Code & Consistency
@@ -115,10 +117,41 @@ CRITICAL (blocks /ship):          INFORMATIONAL (in PR body):
                                    ├─ Time Window Safety
                                    ├─ Type Coercion at Boundaries
                                    └─ View/Frontend
+
+All findings are actioned via Fix-First Review. Severity determines
+presentation order and classification of AUTO-FIX vs ASK — critical
+findings lean toward ASK (they're riskier), informational findings
+lean toward AUTO-FIX (they're more mechanical).
 ```
 
 ---
 
+## Fix-First Heuristic
+
+This heuristic is referenced by both `/review` and `/ship`. It determines whether
+the agent auto-fixes a finding or asks the user.
+
+```
+AUTO-FIX (agent fixes without asking):     ASK (needs human judgment):
+├─ Dead code / unused variables            ├─ Security (auth, XSS, injection)
+├─ N+1 queries (missing .includes())      ├─ Race conditions
+├─ Stale comments contradicting code       ├─ Design decisions
+├─ Magic numbers → named constants         ├─ Large fixes (>20 lines)
+├─ Missing LLM output validation           ├─ Enum completeness
+├─ Version/path mismatches                 ├─ Removing functionality
+├─ Variables assigned but never read       └─ Anything changing user-visible
+└─ Inline styles, O(n*m) view lookups        behavior
+```
+
+**Rule of thumb:** If the fix is mechanical and a senior engineer would apply it
+without discussion, it's AUTO-FIX. If reasonable engineers could disagree about
+the fix, it's ASK.
+
+**Critical findings default toward ASK** (they're inherently riskier).
+**Informational findings default toward AUTO-FIX** (they're more mechanical).
+
+---
+
 ## Suppressions — DO NOT flag these
 
 - "X is redundant with Y" when the redundancy is harmless and aids readability (e.g., `present?` redundant with `length > 20`)