feat(launcher): implement force-sync and chronological download priority

Onsite operators can now manually trigger a full pre-sync of all location
materials via a "Force Sync Location" button in the Launcher config.
This ensures podium Macs have all content cached before an event starts.

- Added trigger__force_location_sync to launcher session store.
- Implemented force_location_sync() in background sync engine to perform
  recursive metadata fetches for all sessions in a location.
- Optimized download queue with a 4-tier chronological sort:
  1. Event/Location assets (Global)
  2. Sessions by start time (Earliest first)
  3. Presentations by start time (Sequential order)
  4. File creation date (First-in fairness for on-time uploads)
- Updated module and native integration documentation.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.ae_brief

@@ -1,22 +1,15 @@
 # Aether Project Brief: aether_app_sveltekit
-**Last Updated:** 2026-02-09 22:03:56
+**Last Updated:** 2026-05-21 22:25:05
 **Current Agent:** mcp_agent
 
 ## 🛠️ What I Just Did
-Addressed multiple Svelte compiler warnings:
-1. Converted ~30 decorative labels to spans (a11y).
-2. Applied Svelte 5 untrack() pattern to initial state from props.
-3. Fixed CSS scoping for TipTap editor.
-4. Added rel="noopener noreferrer" to external links.
-5. Commited changes in two atomic batches.
+Implemented "Force Sync Location" feature. Optimized file download order with a 4-tier chronological sort (Global > Session > Presentation > Creation Date). Added UI button for onsite operators. Updated project documentation. Verified with npm run check.
 
 ## 🚧 Current Blockers
-None. Remaining svelte-check warnings (219) require more granular ID/for linking in complex forms.
+None.
 
 ## ➡️ Exact Next Steps
-1. Granular fix for remaining 68 label/ID associations in address/person forms.
-2. Systematic application of untrack() for remaining state-from-props warnings.
-3. Clean up unused TipTap CSS selectors identified by svelte-check.
+User to review changes. Ready for onsite testing/deployment.
 
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 *Generated by ae_brief*