[codex] complete XR roadmap items and prepare 2.7.12

[ignacio82]

What changed

• complete roadmap items 30-32: chunk bulk-download worker requests below the WorkManager data limit, migrate the XR player root path to the current SceneCore Entity APIs, and render spatialfin.glb with Compose XR SpatialGltfModel
• keep the paused mascot out of the subspace unless playback is actually paused and its delayed reveal has elapsed
• prevent Galaxy XR pause-button gestures from moving the video root by suspending MovableComponent only while a pointer gesture is active inside ControlPanelUI
• restore normal video repositioning and hidden-control reveal behavior by leaving movement enabled while controls are merely visible and retaining the control panel resize policy
• bump the store release to 2.7.12 (libre version code 113, tv version code 1000113) and update roadmap/build guidance

Why

The XR DP4 migration removes deprecated SceneCore model/entity management from the paused mascot path. During device testing, opacity-based hiding of SpatialGltfModel did not prevent the mascot from rendering while video played. Additional headset testing exposed that repeated pause-button selection could be treated as a drag by the movable video root because controls and video use separate projected SceneCore roots.

An initial attempt detached movement whenever an overlay was displayed; that was too broad and prevented both control-panel reveal and intentional video movement. The follow-up scopes input arbitration to an active gesture on the controls only, consistent with Compose XR's movable-panel behavior.

Impact

• bulk episode downloads no longer risk oversized WorkManager input payloads
• the Galaxy XR paused mascot appears only after playback is paused
• control button interaction does not leave the video root movable for the same pointer gesture
• the video remains movable when the control panel is present and controls can be revealed after hiding
• signed Google Play bundle outputs are ready locally for both universal/XR and TV tracks

Verification

• ./gradlew versionCatalogUpdate --console=plain (no catalog changes)
• ./gradlew :player:xr:ktfmtFormat :player:xr:ktfmtCheck :player:xr:compileDebugKotlin :app:unified:assembleLibreDebug --console=plain
• ./gradlew :app:unified:bundleLibreRelease :app:unified:bundleTvRelease --console=plain (rebuilt after input-arbitration correction)
• git diff --check
• installed dev.spatialfin.debug version 2.7.12 (versionCode=113) on connected Galaxy XR device SM-I610 for physical retesting

Store artifacts generated locally

• app/unified/build/outputs/bundle/libreRelease/spatialfin-libre-release.aab (sha256 0790d4a1ef974c9a03119941778ad84bcc21a4d62515590d18221fb2d32ff1f2)
• app/unified/build/outputs/bundle/tvRelease/spatialfin-tv-release.aab (sha256 1b44a0485d501b4aab91d5fd2d268c69d2f90969d5338182b8eec06854eeb06a)