fix: remove trailing newlines from migrations to prevent SQLITE_MISUSE errors

Python's sqlite3.executescript() has a bug where trailing newlines after
the final semicolon create empty statements. When APSW's log_sqlite() is
enabled (via apswutils, imported by fastmigrate), these cause visible
"API called with NULL prepared statement" errors during interpreter shutdown.

- Strip trailing newlines from all 9 existing migration files
- Update migration template to end with semicolon, no trailing newline
- Document the requirement in CLAUDE.md

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

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

CLAUDE.md

@@ -80,6 +80,11 @@ When handling animal selections:
 - Store feed amounts in grams (INTEGER) for precision
 - Display as kg with 3 decimals
 
+### Migrations
+- Migration files must end with `;` and NO trailing newline
+- Python's sqlite3.executescript() has a bug: trailing newlines after the final `;` create empty statements that cause SQLITE_MISUSE errors when APSW logging is enabled
+- Use `animaltrack create-migration "description"` to create new migrations (template handles this correctly)
+
 ## Refreshing Docs
 ```bash
 # FastHTML

src/animaltrack/migrations.py

@@ -94,12 +94,13 @@ def create_migration(migrations_dir: str | Path, description: str) -> Path:
     filepath = migrations_path / filename
 
     # SQL template with ABOUTME header
+    # NOTE: Template must NOT end with trailing newline after final semicolon.
+    # Python's sqlite3.executescript() has a bug where trailing newlines create
+    # empty statements that cause SQLITE_MISUSE errors when APSW logging is enabled.
     template = f"""-- ABOUTME: Migration {index:04d} - {description}
 -- ABOUTME: Created for AnimalTrack database schema versioning.
 
--- Write your migration SQL here
-
-"""
+-- Write your migration SQL here;"""
 
     filepath.write_text(template)
     return filepath