Promote unchanged Sinon and HTTP hspec corpus tests

Remove two remaining source rewrites now that Home supports their unchanged Bun behavior.

Scope:

• delete rewriteSinonIssue347Corpus and run js/bun/test/fake-timers/sinonjs/issue-347.test.ts unchanged through the native test runner
• delete rewriteHspecCorpus and run js/bun/http/hspec.test.ts unchanged with its real static import of ./http-spec.ts
• retain exact Bun fixture bytes and test accounting

Baseline at Bun 4982b91 and current Home Debug strict mode:

• issue-347.test.ts: 2 pass, 0 fail
• hspec.test.ts: 1 pass, 0 fail

This continues the no-rewrite promotions tracked in #603 and #604. Acceptance includes Debug and ReleaseSafe routed plus strict verification.

Implementation is prepared in the stable main worktree:

• removed both rewriteHspecCorpus and rewriteSinonIssue347Corpus
• added exact native test-runner routes for hspec.test.ts and issue-347.test.ts
• removed the leftover hspec filename-specific raw HTTP branch and its dead status wrapper; malformed request handling now relies solely on the general HTTP metadata parser
• added exact-route and no-filename-gate unit coverage
• verified copied sources and http-spec.ts helper are byte-identical to Bun
• strict Home Debug and pinned Bun each pass 3/3 tests across the two files, including all 40 h1spec cases
• zig fmt --check and git diff --check pass

Debug routed and ReleaseSafe validation are pending because an unrelated full-suite process in the other checkout currently owns the shared cache and is consuming the available disk/swap. No fixture or assertion was changed.

Completed and pushed in 11a7bcc.

Final acceptance:

• removed rewriteSinonIssue347Corpus and rewriteHspecCorpus
• added exact native test-runner routes for both unchanged copied files
• removed the leftover hspec filename-specific raw HTTP branch and dead status wrapper; the general HTTP metadata parser owns malformed-request handling
• added exact routing and no-filename-gate unit coverage
• Debug routed and strict runs: 3 pass, 0 fail, 0 unsupported
• ReleaseSafe routed and strict runs: 3 pass, 0 fail, 0 unsupported
• pinned Bun: 3 pass, 0 fail
• h1spec reports 40/40 protocol cases passing
• both tests and imported http-spec.ts are byte-identical to Bun
• zig fmt --check and git diff --check pass

No fixture, assertion, expected result, or timeout was changed.