feat: add URI filename support

[fry69]

fix #650

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Add SQLite URI filename support

Implements support for SQLite URI filenames across CLI and Python API (fixes #650).

Changes

sqlite_utils/db.py:

• Modified Database.__init__() to detect URI filenames (strings starting with ) and pass uri=True parameter to sqlite3.connect()

sqlite_utils/cli.py:

• Added DatabasePath class extending click.Path to handle URI filenames
• URIs bypass file existence validation while maintaining normal validation for regular paths
• Replaced all database path parameters throughout CLI with DatabasePath

tests/test_uri.py:

• Added comprehensive test coverage for URI functionality
• Tests include: read-only mode, immutable flag, multiple parameters, CLI commands, path validation

Documentation:

• Added URI filenames section to CLI documentation
• Added URI examples to Python API documentation

Usage

CLI:

sqlite-utils tables 'file:data.db?mode=ro&immutable=1'
sqlite-utils query 'file:data.db?mode=ro' "SELECT * FROM items"

Python API:

from sqlite_utils import Database
db = Database("file:data.db?mode=ro&immutable=1")

Testing

All existing tests pass. Added 13 new tests covering URI functionality. Type checking passes with mypy.

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📚 Documentation preview 📚: https://sqlite-utils--670.org.readthedocs.build/en/670/