Strengthen final floor guidance and ending

[SilverSupplier]

Summary

• Strengthen the final-floor completion moment with a dedicated celebration state, layered pulse effects, and a clearer HUD label before the report opens.
• Rewrite the ending report as a reflective completion summary with total attempts, most-used base/overlay, discovered reactions, average glyph stability, and log path.
• Add final-floor goal guidance so the HUD shows remaining requirements, the floor progress line names the next target, and the Magic Note updates after each completed requirement.
• Add world-space labels for the six final-floor requirements and switch completed labels to a stronger completed state.
• Add PlayMode coverage for the final seal celebration timing, ending report contents, and final-floor next-goal guidance.

Related Issues

• Closes: [Child #17] 5층 성좌심 목표 가독성 개선 #48, [Child #17] final seal completion/ending presentation 강화 #49
• Related: [Unity] 5층 final seal challenge와 층별 연출 polish #17, Strengthen final floor guidance and ending #63, Differentiate floor 3 and 4 world reactions #65
• Follow-up:

Merge Order

• Preferred: merge Feat: tune Magic Exam Hall world casting timing #58 first, then re-check this PR because Feat: tune Magic Exam Hall world casting timing #58 touches world-casting timing and goal targeting.
• Differentiate floor 3 and 4 world reactions #65 is functionally separate but also edits ExamGameController.cs and PlayMode smoke tests. Whichever of Strengthen final floor guidance and ending #63/Differentiate floor 3 and 4 world reactions #65 lands second should resolve conflicts and re-run Unity PlayMode/EditMode tests.
• This PR intentionally keeps the final-floor guidance work separate from floor 3/4 reaction differentiation in Differentiate floor 3 and 4 world reactions #65.

Verification

• node scripts/validate-doc-state.mjs
• Unity PlayMode tests: 8 passed
• Unity EditMode tests: 19 passed
• npm test; Not run locally, Unity-only change and local node_modules is not installed.
• npm run build; Not run locally, Unity-only change and local node_modules is not installed.
• GitHub checks observed after latest push: validate-docs, build, test, and CodeQL passed.

Notes

• Scope: final-floor HUD copy, final-floor world goal labels, Magic Note next-goal guidance, final completion celebration, ending report copy, and PlayMode regression coverage.
• Out of scope / follow-up: floor 3/4 reaction differentiation and localized combo targeting from Differentiate floor 3 and 4 world reactions #65.
• Risk notes: the new world labels are only created for floor 5 to avoid cluttering earlier tutorial floors. Merge conflicts with Differentiate floor 3 and 4 world reactions #65 are likely because both PRs touch the same controller and smoke test file.

Review Checklist

• This PR changes user-facing UI or behavior.
• This PR changes recognizer behavior.
• This PR changes docs, task state, or project process.
• This PR changes ML artifacts, datasets, generated outputs, or capture/export behavior.
• This PR changes logging, survey fields, privacy, or research data handling.
• This PR needs screenshots or a short playtest note.

Screenshots / Playtest Notes

Batchmode PlayMode confirms the final floor starts with a visible next-goal hint, updates that hint after completing the first final requirement, shows the final seal celebration before the report, and renders the reflective ending report contents.