refactor: convert f-string logging to lazy %-style format (G004)

Sweep all 1676 G004 violations across 112 files, converting
`logger.<level>(f"…{x}…")` to `logger.<level>("…%s…", x)`.

Why: ruff rule G004 was added to pyproject.toml to enforce lazy
%-style logging — defers formatting until the log level is enabled
and lets structured log tooling match the unformatted template.

Conversion preserves rendered output byte-for-byte:
- `{x}` → `%s` + `x`
- `{x!r}` / `{x!s}` / `{x!a}` → `%r` / `%s` / `%a`
- Format specs (`{x:.2f}`, `{x:>10}`) → `%s` + `format(x, 'spec')`
  (printf-style specs aren't 1:1 with Python format specs, so we
  delegate to `format()` to keep identical output)
- Literal `%` → `%%`
- Concatenated f-strings (`f"a {x} " "b"`) flattened
- Trailing kwargs (`exc_info=True`) preserved

Verified:
- `uv run ruff check --select G004` → 0 violations
- `uv run ty check -- nextcloud_mcp_server` → passes
- `uv run pytest tests/unit/` → 1010 passed

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

tests/client/test_sharing_api.py

@@ -39,7 +39,7 @@ async def test_create_and_delete_share(nc_client):
         assert share_data is not None
         assert "id" in share_data
         share_id = share_data["id"]
-        logger.info(f"Created share: {share_id}")
+        logger.info("Created share: %s", share_id)
 
         # Get share info
         share_info = await nc_client.sharing.get_share(share_id)
@@ -56,7 +56,7 @@ async def test_create_and_delete_share(nc_client):
         # Cleanup
         if share_id:
             await nc_client.sharing.delete_share(share_id)
-            logger.info(f"Deleted share: {share_id}")
+            logger.info("Deleted share: %s", share_id)
 
         await nc_client.webdav.delete_resource(file_path)