feat(dashboard): require config_hash, remove card tools, add hints

BREAKING CHANGE: Remove ha_dashboard_add_card, ha_dashboard_update_card,
ha_dashboard_remove_card tools. Use jq_transform in ha_config_set_dashboard
instead for all card operations.

Changes:
- config_hash now REQUIRED for jq_transform (optimistic locking)
- config_hash optional for full config replacement (validates if provided)
- Add card_count and hint to get_dashboard for large dashboards (30+ cards)
- Add soft warning when full-replacing large dashboards
- Document multi-op jq syntax with pipe chaining
- Add IMPORTANT warning about index shifting after delete/add ops
- Add ENABLE_DASHBOARD_PARTIAL_TOOLS feature flag for find_card
- Remove 726 lines of redundant card tool code

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: julienld

src/ha_mcp/config.py

@@ -69,6 +69,11 @@ class Settings(BaseSettings):
     # Examples: "tools_config_automations,tools_config_scripts,tools_traces"
     enabled_tool_modules: str = Field("all", alias="ENABLED_TOOL_MODULES")
 
+    # Dashboard partial update tools (jq_transform, find_card)
+    # These are token-efficient alternatives to full config replacement.
+    # Disable when using clients with programmatic tool use (future).
+    enable_dashboard_partial_tools: bool = Field(True, alias="ENABLE_DASHBOARD_PARTIAL_TOOLS")
+
     @property
     def env_file_name(self) -> str:
         """Get the current environment file name."""