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/server/test_error_propagation.py

@@ -40,7 +40,7 @@ async def test_search_with_empty_query(nc_mcp_client: ClientSession):
     # Search with empty query
     response = await nc_mcp_client.call_tool("nc_notes_search_notes", {"query": ""})
 
-    logger.info(f"Empty search query response: {response}")
+    logger.info("Empty search query response: %s", response)
 
     # Should return successful response with empty or valid results
     assert response is not None
@@ -54,7 +54,7 @@ async def test_tool_missing_required_parameters(nc_mcp_client: ClientSession):
         "nc_notes_create_note",
         {"title": "Test"},  # Missing content and category
     )
-    logger.info(f"Missing params response: {response}")
+    logger.info("Missing params response: %s", response)
 
     # Should return error response for missing required parameters
     assert response is not None
@@ -108,7 +108,7 @@ async def test_calendar_missing_calendar_error(nc_mcp_client: ClientSession):
         },
     )
 
-    logger.info(f"Non-existent calendar response: {response}")
+    logger.info("Non-existent calendar response: %s", response)
 
     # Should return structured error response
     assert response is not None
@@ -131,7 +131,7 @@ async def test_webdav_read_missing_file_error(nc_mcp_client: ClientSession):
         "nc_webdav_read_file", {"path": "non-existent-file.txt"}
     )
 
-    logger.info(f"Missing file response: {response}")
+    logger.info("Missing file response: %s", response)
 
     # Should return structured error response
     assert response is not None
@@ -154,7 +154,7 @@ async def test_tables_missing_table_error(nc_mcp_client: ClientSession):
         "nc_tables_get_schema", {"table_id": 999999}
     )
 
-    logger.info(f"Missing table response: {response}")
+    logger.info("Missing table response: %s", response)
 
     # Should return structured error response
     assert response is not None