chore(tooling): anchor coverage excludes, fix pre-commit hooks, tidy ruff ignores

[allen0099]

Summary

Closes #190, closes #191, closes #192 (parts of #124).

#190: anchor the coverage exclude patterns

The patterns "pass" and "\\.\\.\\." are regexes searched anywhere in a line. An excluded line that opens a block excludes the whole block. So they hid more than the issue listed:

• the entire AsyncRedisCacheBackend.__init__ body (lines 109–181), through its password parameter;
• bypass_backend = ... and the if bypass_backend: branch in @cache;
• Field(...) lines and a clear_pattern warning that says "pass".

They are now anchored to bare pass / ... statements, optionally followed by a comment.

Coverage below was measured locally with the live Redis/Memcached tests skipped, so it is lower than CI's live run:

	Statements	Coverage
before	2372	93.86%
after	2419	93.90%

That is 47 more statements counted. Only one of them is uncovered locally: a Redis warning line (redis.py:447) that the live tests exercise.

fail_under stays at 90. A run without live servers sits at about 94%, so raising it past ~93 would fail local runs that have no servers. A separate, higher gate for the live CI job would be the place to raise it.

#191: pre-commit

• Removed the second end-of-file-fixer.

• uv-lock no longer runs with --upgrade, so pre-commit no longer bumps uv.lock. This PR was committed with every hook running, and no SKIP=uv-lock was needed.

• The mypy hook's additional_dependencies:

  • dropped types-requests, types-PyYAML and types-aiofiles; nothing imports them;
  • added redis, orjson, pymemcache and PyJWT, the optional packages the code imports.

  No new mypy errors surfaced.

• docs/DEVELOPMENT.md now says uv-lock only re-resolves the lockfile and does not upgrade it.

#192: ruff ignores

• PLW0603: the per-file ignore on proxy.py was stale (no global left) and is removed.
• B904 was not stale. Two optional-import guards re-raised without from, in memcached.py and redis.py. They now chain the ImportError (raise CacheXError(msg) from exc), and the global ignore is removed.
• S105 moved to per-file ignores:
  • session/manager.py: token_format = "simple" is not a password;
  • tests/**.
• PLR0917 moved to the two public constructors that need it, in backends/redis.py and lock.py. The private _persist helper in session/middleware.py got an inline noqa, next to its existing PLR0913.
• B008 is replaced by lint.flake8-bugbear.extend-immutable-calls = ["fastapi.Depends"]. Depends is the only call B008 flags, in both the package and the tests.
• CLAUDE.md is updated to match.

Verification

• uv run pre-commit run --all-files: passes, and uv.lock is byte-identical afterwards.
• uv lock --check: passes.
• uv run mypy fastapi_cachex --strict: clean.
• uv run ruff check fastapi_cachex tests scripts: clean. Also ran it with only --select PLW0603 and only --select B904: both clean.
• uv run pytest with live servers skipped: 814 passed, 191 skipped.
• zensical build --strict for the English docs passes. DEVELOPMENT.md has no zh-TW copy.

CHANGELOG

None: tooling only. The one library change is that the "not installed" CacheXError now chains the original ImportError, and I judged it too small for an entry.