feat(KB-619): add multi-project CLI support

- Add project-resolver module with CentralCore integration for project resolution
- Add project subcommands: list, add, remove, info with proper CLI integration
- Add --project flag support across all task and settings commands
- Refactor getStore to use project resolution with options pattern
- Update bin.ts command routing to extract and propagate project context
- Add project context propagation via FN_PROJECT environment variable

packages/core/src/types.ts

@@ -529,8 +529,9 @@ export interface GlobalSettings {
   /** ntfy.sh topic name for push notifications. When set along with ntfyEnabled,
    *  notifications are sent to https://ntfy.sh/{topic} when tasks complete or fail. */
   ntfyTopic?: string;
-  /** Default project ID for the current user. Used to automatically select
-   *  the default project when opening the dashboard without a specific project. */
+  /** Default project ID to use when no explicit project is specified and
+   *  no project can be auto-detected from the current directory.
+   *  Used for multi-project CLI workflows. */
   defaultProjectId?: string;
 }