Refresh pinned commands when actions change

[multiplex55]

Motivation

• Ensure the pinned commands widget rebuilds its cache when the pinned list itself changes and when in-memory actions are updated so the dashboard always shows current items.
• Guarantee dashboard widgets observe action updates even if saving to disk fails or is deferred by bumping the global actions version when actions are added/edited.

Description

• Track a hash of cfg.action_ids by adding last_action_ids_hash and action_ids_hash(...), and include that hash in refresh_cache so the cache is rebuilt when the pinned list changes.
• Call crate::actions::bump_actions_version() after app.update_action_cache() in the add/edit branches of the action dialog to surface in-memory changes to the dashboard immediately.
• Add unit tests in src/dashboard/widgets/pinned_commands.rs that verify (1) changing cfg.action_ids forces a cache refresh and (2) bumping actions_version causes cached actions to be rebuilt, using a minimal DashboardContext and DashboardDataCache::new().

Testing

• Ran targeted tests with cargo test for the new tests; the build started but failed due to a missing system dependency required by alsa-sys (pkg-config/alsa.pc), so the test run did not complete.
• The new unit tests are included and should pass in an environment where the alsa development pkg (or appropriate build flags/environment) is available so the project can compile and run tests successfully.

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Codex Task