Fix: Use short git commit ID (7 chars) instead of full hash

Research findings:
- Industry standard uses 'git rev-parse --short HEAD' (7 characters)
- Short hashes are more readable for logs and health endpoints
- Git automatically extends hash if 7 chars aren't unique
- Better for production deployment tracking and version verification

Changes:
- Dockerfile: Use --short flag to get 7-character commit ID
- README: Update examples to show short commit format (0e993d9)
- README: Add explanation of why short commits are used

Example health response:
{
  "git_commit": "0e993d9",  // 7 chars, not full 40-char SHA
  "version": "1.0.0"
}

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

Dockerfile

@@ -16,9 +16,9 @@ RUN npm install --production
 # Copy app code (changes more often — below the cached layer)
 COPY . .
 
-# Try to get git commit if not provided and .git exists
+# Try to get short git commit (7 chars) if not provided and .git exists
 RUN if [ "$GIT_COMMIT" = "unknown" ] && [ -d .git ]; then \
-      GIT_COMMIT=$(git rev-parse HEAD 2>/dev/null || echo "unknown"); \
+      GIT_COMMIT=$(git rev-parse --short HEAD 2>/dev/null || echo "unknown"); \
     fi && \
     echo "export GIT_COMMIT=${GIT_COMMIT}" >> /etc/profile.d/git-version.sh
 

README.md

@@ -284,7 +284,7 @@ curl https://template-001.startanaicompany.com/health
 #   "postgres": "connected",
 #   "redis": "connected",
 #   "timestamp": "2026-02-14T10:30:00.000Z",
-#   "git_commit": "eb6b6e0...",
+#   "git_commit": "0e993d9",
 #   "version": "1.0.0"
 # }
 
@@ -416,7 +416,7 @@ Health check endpoint that verifies connections to PostgreSQL and Redis, and ret
   "postgres": "connected",
   "redis": "connected",
   "timestamp": "2026-02-14T10:30:00.000Z",
-  "git_commit": "eb6b6e0a1b2c3d4e5f6g7h8i9j0k1l2m3n4o5p6q",
+  "git_commit": "0e993d9",
   "version": "1.0.0"
 }
 ```
@@ -426,16 +426,16 @@ Health check endpoint that verifies connections to PostgreSQL and Redis, and ret
 {
   "status": "unhealthy",
   "error": "Connection error message",
-  "git_commit": "eb6b6e0a1b2c3d4e5f6g7h8i9j0k1l2m3n4o5p6q",
+  "git_commit": "0e993d9",
   "version": "1.0.0"
 }
 ```
 
 **Version Tracking:**
-- `git_commit`: The Git commit SHA of the deployed code (auto-detected during build)
+- `git_commit`: Short Git commit SHA (7 characters) of the deployed code, auto-detected during build using `git rev-parse --short HEAD`
 - `version`: Application version (defaults to 1.0.0, can be set via APP_VERSION env var)
 
-This allows AI agents and monitoring tools to verify which version is currently running.
+This allows AI agents and monitoring tools to verify which version is currently running. The short commit ID is industry standard for deployment tracking, providing a balance between uniqueness and readability.
 
 ---