fix(plugin-system): unload/update race, failed-load cleanup, limits validation, schema lookup, install rollback (#653)

* fix(plugin-system): unload/update race, failed-load module cleanup, limits validation, schema lookup, install rollback, op-queue dedupe

- unload_plugin takes the per-plugin lock (5s bounded) before cleanup(),
  and an update() that finishes after its plugin was unloaded no longer
  sets the state back to ENABLED.
- A load that fails after import drops plugin_<id> and its submodules
  and forgets its manager fonts, so a fixed plugin reloads new code.
- Resource limits are validated as non-negative numbers: 400 at
  POST /plugins/limits, bad cached records ignored with one warning.
  Route docstrings note health/metrics reset and limits only change the
  web process's view.
- SchemaManager.get_schema_path resolves each search dir via
  resolve_plugin_dir (manifest id, ledmatrix-<id>) before the literal
  paths; plugins/ still before plugin-repos/. Misses cached 30s and
  logged once at DEBUG.
- install_from_url sets an existing copy aside and restores it if the
  move fails, under the per-plugin reinstall lock.
- Operation queue refuses a second pending op for a plugin and trims
  _operations with history.
- get_vegas_render_width reads display_manager.width first.
- get_logger in store/schema/health/resource/saved_repositories;
  UTF-8 reads in store_manager and state_manager.
- Docs: update_interval precedence (manifest over config) stated where
  users are told to set it in config.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* fix(web): build the limits 400 message from the field name, not an exception

CodeQL flagged str(e) flowing into the response. invalid_limit_field()
returns the offending field without raising, and limits_from_dict uses it.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>

src/plugin_system/saved_repositories.py

@@ -5,11 +5,11 @@ Manages saved GitHub repository URLs for easy plugin discovery and installation.
 """
 
 import json
-import logging
 import os
 from pathlib import Path
 from typing import List, Dict, Optional
 
+from src.logging_config import get_logger
 from src.plugin_system.repo_urls import normalize_repo_url
 
 
@@ -24,7 +24,7 @@ class SavedRepositoriesManager:
             config_path: Path to JSON file storing saved repositories
         """
         self.config_path = Path(config_path)
-        self.logger = logging.getLogger(__name__)
+        self.logger = get_logger(__name__)
         self.repositories = self._load_repositories()
     
     def _load_repositories(self) -> List[Dict[str, str]]: