feat: Implement v1.1.1 Phase 1 - Core Infrastructure

Phase 1 of v1.1.1 "Polish" release focusing on production readiness.
Implements logging, connection pooling, validation, and error handling.

Following specs in docs/design/v1.1.1/developer-qa.md and ADRs 052-055.

**Structured Logging** (Q3, ADR-054)
- RotatingFileHandler (10MB files, keep 10)
- Correlation IDs for request tracing
- All print statements replaced with logging
- Context-aware correlation IDs (init/request)
- Logs written to data/logs/starpunk.log

**Database Connection Pooling** (Q2, ADR-053)
- Connection pool with configurable size (default: 5)
- Request-scoped connections via Flask g object
- Pool statistics for monitoring
- WAL mode enabled for concurrency
- Backward compatible get_db() signature

**Configuration Validation** (Q14, ADR-052)
- Validates presence and type of all config values
- Fail-fast startup with clear error messages
- LOG_LEVEL enum validation
- Type checking for strings, integers, paths
- Non-zero exit status on errors

**Centralized Error Handling** (Q4, ADR-055)
- Moved handlers to starpunk/errors.py
- Micropub spec-compliant JSON errors
- HTML templates for browser requests
- All errors logged with correlation IDs
- MicropubError exception class

**Database Module Reorganization**
- Moved database.py to database/ package
- Separated init.py, pool.py, schema.py
- Maintains backward compatibility
- Cleaner separation of concerns

**Testing**
- 580 tests passing
- 1 pre-existing flaky test noted
- No breaking changes to public API

**Documentation**
- CHANGELOG.md updated with v1.1.1 entry
- Version bumped to 1.1.1
- Implementation report in docs/reports/

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

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

starpunk/config.py

@@ -111,6 +111,12 @@ def validate_config(app):
     """
     Validate application configuration on startup
 
+    Per ADR-052 and developer Q&A Q14:
+    - Validates at startup (fail fast)
+    - Checks both presence and type of required values
+    - Provides clear error messages
+    - Exits with non-zero status on failure
+
     Ensures required configuration is present based on mode (dev/production)
     and warns prominently if development mode is enabled.
 
@@ -118,8 +124,60 @@ def validate_config(app):
         app: Flask application instance
 
     Raises:
-        ValueError: If required configuration is missing
+        ValueError: If required configuration is missing or invalid
     """
+    errors = []
+
+    # Validate required string fields
+    required_strings = {
+        'SITE_URL': app.config.get('SITE_URL'),
+        'SITE_NAME': app.config.get('SITE_NAME'),
+        'SITE_AUTHOR': app.config.get('SITE_AUTHOR'),
+        'SESSION_SECRET': app.config.get('SESSION_SECRET'),
+        'SECRET_KEY': app.config.get('SECRET_KEY'),
+    }
+
+    for field, value in required_strings.items():
+        if not value:
+            errors.append(f"{field} is required but not set")
+        elif not isinstance(value, str):
+            errors.append(f"{field} must be a string, got {type(value).__name__}")
+
+    # Validate required integer fields
+    required_ints = {
+        'SESSION_LIFETIME': app.config.get('SESSION_LIFETIME'),
+        'FEED_MAX_ITEMS': app.config.get('FEED_MAX_ITEMS'),
+        'FEED_CACHE_SECONDS': app.config.get('FEED_CACHE_SECONDS'),
+    }
+
+    for field, value in required_ints.items():
+        if value is None:
+            errors.append(f"{field} is required but not set")
+        elif not isinstance(value, int):
+            errors.append(f"{field} must be an integer, got {type(value).__name__}")
+        elif value < 0:
+            errors.append(f"{field} must be non-negative, got {value}")
+
+    # Validate required Path fields
+    required_paths = {
+        'DATA_PATH': app.config.get('DATA_PATH'),
+        'NOTES_PATH': app.config.get('NOTES_PATH'),
+        'DATABASE_PATH': app.config.get('DATABASE_PATH'),
+    }
+
+    for field, value in required_paths.items():
+        if not value:
+            errors.append(f"{field} is required but not set")
+        elif not isinstance(value, Path):
+            errors.append(f"{field} must be a Path object, got {type(value).__name__}")
+
+    # Validate LOG_LEVEL
+    log_level = app.config.get('LOG_LEVEL', 'INFO').upper()
+    valid_log_levels = ['DEBUG', 'INFO', 'WARNING', 'ERROR', 'CRITICAL']
+    if log_level not in valid_log_levels:
+        errors.append(f"LOG_LEVEL must be one of {valid_log_levels}, got '{log_level}'")
+
+    # Mode-specific validation
     dev_mode = app.config.get("DEV_MODE", False)
 
     if dev_mode:
@@ -133,14 +191,29 @@ def validate_config(app):
 
         # Require DEV_ADMIN_ME in dev mode
         if not app.config.get("DEV_ADMIN_ME"):
-            raise ValueError(
+            errors.append(
                 "DEV_MODE=true requires DEV_ADMIN_ME to be set. "
                 "Set DEV_ADMIN_ME=https://your-dev-identity.example.com in .env"
             )
     else:
         # Production mode: ADMIN_ME is required
         if not app.config.get("ADMIN_ME"):
-            raise ValueError(
+            errors.append(
                 "Production mode requires ADMIN_ME to be set. "
                 "Set ADMIN_ME=https://your-site.com in .env"
             )
+
+    # If there are validation errors, fail fast with clear message
+    if errors:
+        error_msg = "\n".join([
+            "=" * 70,
+            "CONFIGURATION VALIDATION FAILED",
+            "=" * 70,
+            "The following configuration errors were found:",
+            "",
+            *[f"  - {error}" for error in errors],
+            "",
+            "Please fix these errors in your .env file and restart.",
+            "=" * 70
+        ])
+        raise ValueError(error_msg)