fix Failover→Fallback naming and missing/stale script references

Failover/ was renamed to Fallback/ — all script paths and README links
updated across README.md, Orchestrators README, and User Script Plug-in README.

array_start.sh → array_started.sh in Orchestrators scripts table (wrong name).

fallback_state_reset.sh: script is referenced in User Script Plug-in README
but does not exist in Fallback/. Entry updated to document it as not yet built
and provides the manual workaround (direct state file write).

Note: /mnt/user/appdata-Failover/ share path references left unchanged —
that is the actual unRAID share name on the server, not the script folder.

Orchestrators/README-Orchestrators.md

@@ -166,7 +166,7 @@ without `--log`.
 
 | Script | What It Orchestrates | Schedule |
 |--------|---------------------|----------|
-| `array_start.sh` | All array startup scripts in order | At Startup of Array |
+| `array_started.sh` | All array startup scripts in order | At Startup of Array |
 | `watchdog_orchestrator.sh` | resource → docker → system → stability watchdogs | Every minute |
 | `transcode_management.sh` | Cleanup then manager — order critical | Every 3 minutes |
 | `arrs_failed_stalled_recovery.sh` | Failed import + stalled download recovery | Every 6 hours |
@@ -222,7 +222,7 @@ ARRAY_START_SCRIPTS=(
     "Watchdogs/docker_watchdog.sh"         # container health BEFORE failover —
                                                    # containers must be healthy for failover
                                                    # to make reliable decisions
-    "Failover/failover.sh"                         # failover LAST — needs everything else stable
+    "Fallback/fallback.sh"                          # fallback LAST — needs everything else stable
 )
 ```