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/load/workloads.py

@@ -182,12 +182,12 @@ class WorkloadOperations:
 
     async def cleanup(self):
         """Clean up any resources created during testing."""
-        logger.info(f"Cleaning up {len(self._created_notes)} test notes...")
+        logger.info("Cleaning up %s test notes...", len(self._created_notes))
         for note_id in self._created_notes[:]:
             try:
                 await self.delete_note(note_id)
             except Exception as e:
-                logger.warning(f"Failed to delete note {note_id}: {e}")
+                logger.warning("Failed to delete note %s: %s", note_id, e)
 
 
 class MixedWorkload:
@@ -210,7 +210,7 @@ class MixedWorkload:
 
     async def warmup(self, count: int = 10):
         """Create initial notes for read/update operations."""
-        logger.info(f"Warming up with {count} test notes...")
+        logger.info("Warming up with %s test notes...", count)
         for _ in range(count):
             result = await self.ops.create_note()
             if result.success and self.ops._created_notes:
@@ -225,7 +225,7 @@ class MixedWorkload:
                         etag = note_data.get("etag", "")
                         self._warmup_note_ids.append((note_id, etag))
                 except Exception as e:
-                    logger.warning(f"Failed to get etag for note {note_id}: {e}")
+                    logger.warning("Failed to get etag for note %s: %s", note_id, e)
 
     async def run_operation(self) -> OperationResult:
         """Execute one random operation based on the workload distribution."""