Add "Change V5.5.0: Hook Efficiency Quick Wins (Sprint 8 Implementation)"

Change-V5.5.0%3A-Hook-Efficiency-Quick-Wins-%28Sprint-8-Implementation%29.md

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+# Change V5.5.0: Hook Efficiency Quick Wins
+
+**Sprint:** 8  
+**Status:** In Progress  
+**Date:** 2026-01-29  
+**Origin:** [RFC-Hook-Efficiency-Improvements](../RFC-Hook-Efficiency-Improvements.-)
+
+---
+
+## Scope
+
+This sprint implements **Phase 1: Quick Wins** from the RFC, focusing on low-effort, high-impact optimizations.
+
+### In Scope
+
+| Change | Plugin | Impact |
+|--------|--------|--------|
+| Remove SessionStart hook | viz-platform | Eliminates pointless echo |
+| Add early git check | git-flow | Skips 90%+ of Bash invocations |
+| Add cooldown | project-hygiene | Reduces find operations |
+
+### Explicitly Out of Scope
+
+- SessionStart dispatcher consolidation (rejected - fights plugin architecture)
+- Shared hook library (rejected - creates coupling)
+- clarity-assist opt-in (deferred - requires user discussion)
+- Path filtering for PostToolUse hooks (deferred - case-by-case)
+
+---
+
+## Implementation Details
+
+### 1. Remove viz-platform SessionStart Hook
+
+**File:** `plugins/viz-platform/hooks/hooks.json`
+
+**Current:**
+```json
+{
+  "hooks": [
+    {
+      "event": "SessionStart",
+      "type": "command",
+      "command": "echo 'viz-platform plugin loaded'",
+      "timeout": 5000
+    }
+  ]
+}
+```
+
+**After:**
+```json
+{
+  "hooks": []
+}
+```
+
+### 2. Add Early Git Check to git-flow Hooks
+
+**Problem:** `commit-msg-check.sh` spawns Python to parse JSON even for non-git commands.
+
+**Solution:** Add early check before JSON parsing:
+```bash
+# Quick check - exit immediately if not a git command
+if ! echo "$INPUT" | grep -q '"command".*git'; then
+    exit 0
+fi
+```
+
+**Files:**
+- `plugins/git-flow/hooks/branch-check.sh`
+- `plugins/git-flow/hooks/commit-msg-check.sh`
+
+### 3. Add Cooldown to project-hygiene
+
+**Problem:** Runs `find` across entire project on every file edit.
+
+**Solution:** Add session-based cooldown (skip if ran recently):
+```bash
+LAST_RUN_FILE="/tmp/project-hygiene-${PPID}-last-run"
+if [[ -f "$LAST_RUN_FILE" ]]; then
+    LAST_RUN=$(cat "$LAST_RUN_FILE")
+    NOW=$(date +%s)
+    if (( NOW - LAST_RUN < 60 )); then
+        exit 0  # Skip if ran in last 60 seconds
+    fi
+fi
+date +%s > "$LAST_RUN_FILE"
+```
+
+---
+
+## Verification
+
+After implementation:
+1. Start new session - should be faster
+2. Run non-git bash commands - no hook overhead
+3. Edit files rapidly - cleanup shouldn't run on every edit
+4. Verify functionality still works when triggered
+
+---
+
+## References
+
+- RFC: [Hook Efficiency Improvements](../RFC-Hook-Efficiency-Improvements.-)
+- Previous analysis identified 16 hooks across 12 plugins