Add generationStatus and match3d/runtime fixes

Introduce persistent generationStatus to work summaries (puzzle & match3d) and propagate generation recovery rules across docs and frontend/backends so "generating" is restored from server-side work summary rather than ephemeral front-end notices. Update API server image/asset handling (improve match3d material sheet green/alpha decontamination and promote generatedItemAssets background fields) and add runtime improvements: alpha-based hotspot hit-testing, tray insertion/three-match animation behavior, and session re-read on client-side VectorEngine timeouts/lock-screen interruptions. Many docs, tests and related frontend modules updated/added to reflect these contract and behavior changes.

server-rs/crates/shared-contracts/src/puzzle_works.rs

@@ -57,6 +57,8 @@ pub struct PuzzleWorkSummaryResponse {
     pub point_incentive_claimable_points: u64,
     pub publish_ready: bool,
     #[serde(default)]
+    pub generation_status: Option<String>,
+    #[serde(default)]
     pub levels: Vec<PuzzleDraftLevelResponse>,
 }
 
@@ -91,6 +93,7 @@ mod tests {
             point_incentive_total_points: 1.5,
             point_incentive_claimable_points: 0,
             publish_ready: true,
+            generation_status: Some("ready".to_string()),
             levels: Vec::new(),
         })
         .expect("payload should serialize");
@@ -99,6 +102,7 @@ mod tests {
         assert_eq!(payload["pointIncentiveClaimedPoints"], 1);
         assert_eq!(payload["pointIncentiveTotalPoints"], 1.5);
         assert_eq!(payload["pointIncentiveClaimablePoints"], 0);
+        assert_eq!(payload["generationStatus"], "ready");
     }
 }