Rename Commons to Game throughout the codebase (closes #276)

[pconrad]

Summary

Closes #276. The user-facing terminology was already renamed from "Commons" to "Game" in #271; this does the same for the code itself: database table/column names, class/file names, method names, parameter names, API routes, and test names, respecting each artifact's case convention (Commons->Game, commons->game, COMMONS->GAME, e.g. commonsId->gameId, CommonsPlus->GamePlus).

Details:

• Renamed 80 source files (entities, controllers, repositories, services, jobs, errors, DTOs, and their frontend/test/story counterparts), including moving the frontend's Commons/ component directory to Game/. Also fixed a pre-existing filename typo (AdminListCommonPageV2.jsx, singular) to match its already-plural component name, now AdminListGamePageV2.jsx.
• Added a new idempotent migration (007_rename_commons_to_game.json, following the same precondition-guarded pattern as the prior two rename migrations from Change UserCommons name to Farmer throughout the app #274/Hotfix: make lib-jobs migration's FK drop idempotent #272) that renames the commons table to game, and the commons_id column (plus its two FK constraints) across every table that references it: farmer, profits, announcement, chat_message, commonstats, cowdeath, and reports.
• The case-aware substitution deliberately protects two collisions:
  • CommonStats — a distinct, unrelated entity/table (Common is singular, not Commons) — via a negative-lookahead regex guarding the literal lowercase commonstats substring used in its API routes (/api/commonstats/*).
  • "Tragedy of the Commons" — the real-world economics term the app is named after — by excluding prose documentation (README, gamePlay.md, copilot-instructions.md) from the bulk substitution entirely, fixing only the one genuinely stale code reference in copilot-instructions.md.
• Caught and reverted a second-order corruption from that same collision risk: pom.xml's actual Apache Commons Maven dependency (org.apache.commons:commons-csv) and its imports across 6 files got mangled to org.apache.game by an earlier, less careful substitution pass and had to be restored — a good reminder that "Commons" the app concept and Apache Commons the library share nothing but a name.

Test plan

• Backend: mvn verify — 379/379 tests, 100% JaCoCo coverage
• Frontend: 742/742 tests, 100% coverage (statements/branches/functions/lines), lint/format clean
• Pitest on all ~58 changed backend classes: 411/411 mutants killed, 100%, 0 survivors
• Stryker on all ~44 changed frontend files: 100% mutation score (0 survivors; met the break threshold)
• Playwright integration suite run locally end-to-end: GameWebIT, FarmerWebIT, and GameIT all pass. DashboardWebIT hits an unrelated pre-existing Playwright flake (element detached from DOM) that reproduces identically on unmodified main — already documented in the Change "Commons" in user facing terminology to something else #271/Change UserCommons name to Farmer throughout the app #274 PRs, not introduced by this change.
• Exhaustive final repo-wide grep confirms zero remaining occurrences of Commons/commons/COMMONS outside: the historical migration files (which must stay byte-identical), the new migration file (which necessarily references the old names as its rename targets), and the legitimate CommonStats/org.apache.commons/"Tragedy of the Commons" exclusions above.

🤖 Generated with Claude Code

[pconrad]

LGTM