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>

documentation/MODULE__AE_Events_PressMgmt_Launcher.md

@@ -169,8 +169,8 @@ per event via config.
 1. **Presenter checks in** — staff looks up their session(s) in Pres Mgmt
 2. **File upload** — staff or presenter uploads file to the correct presenter/session record
 3. **File verification** — staff opens the file on a practice station to confirm it renders
-4. **Launcher sync** — file appears in the Launcher within the next polling cycle
-5. **Presenter proceeds to room** — podium kiosk already has the file cached
+4. **Launcher Sync** — file appears in the Launcher within the next polling cycle. Staff can use the **Force Sync Location** button in the Launcher config to immediately queue all files for the room's schedule.
+5. **Presenter proceeds to room** — podium kiosk already has the file cached.
 
 ---
 
@@ -280,6 +280,18 @@ For production onsite use, **Native mode on Mac laptops** is the target. The Ele
 app pre-caches all session files in the background so presentations open instantly without
 a network round-trip at the moment of launch.
 
+### Download Priority & Room Readiness
+
+To ensure the podium is ready for the day's first sessions, the Launcher sync engine uses a
+4-tier chronological sorting priority:
+
+1.  **Global Assets:** Event and Location level files (branding, walk-in slides) are cached first.
+2.  **Session Schedule:** Files for the earliest sessions in the room are prioritized.
+3.  **Presentation Order:** Within a session block, speakers are prioritized by their scheduled start time.
+4.  **First-In Fairness:** When times are equal, older uploads are prioritized over late revisions.
+
+Operators can manually trigger a full pre-sync of all location materials via the **Force Sync Location** button in the Launcher configuration (Sync Engine section).
+
 ### Native Mode — Electron App
 
 - **Repo:** `~/OSIT_dev/aether_app_native_electron/`