feat: add FreshLoop demonstration video and optimize delivery

[DrEden33773]

Summary

• add the independent FreshLoopDemo Remotion composition while preserving the existing 90-second FreshLoopIntro
• integrate the recorded English narration and real emulator footage with complete audio boundaries and final-frame holds
• compact the Moodle application-source archive and validate exact archive freshness
• gate every CI job by its relevant path domain, with dedicated video and source-package contract jobs

Validation

• video TypeScript check and 9/9 video contract tests
• 5:00-bounded demo asset/render QA with real footage and complete narration boundaries
• compact source archive validator, full Intro decode, ZIP CRC, clean extraction, 58/58 Jest suites and 162/162 app tests
• 9/9 CI path/source-package contract tests

Delivery boundary

• no Moodle submission is performed by this PR
• FreshLoopIntro remains a separate 1920x1080, 60fps, 5400-frame composition
• the generated submission binaries remain excluded from Git history; their hashes and reproducible commands are recorded in repository evidence