test(replay): session-replay-vars.test.ts (2,299 lines) tests everything except its namesake — split by actual subject #1460

Context

src/daemon/handlers/__tests__/session-replay-vars.test.ts (2,299 lines, 65 tests, 0 describe blocks) contains zero references to buildReplayBuiltinVars — the only export of the module it is named after (src/daemon/handlers/session-replay-vars.ts, whose real test lives next door in the correctly-named session-replay-builtin-vars.test.ts). What it actually contains (verified 2026-07-28):

1. ~450 lines testing src/replay/vars.ts (buildReplayVarScope, resolveReplayString, collectReplayShellEnv, parseReplayCliEnvEntries, resolveReplayAction) — a module with real precedence/escaping logic and no test file of its own name anywhere.
2. ~15 tests of parseReplayScriptDetailed/readReplayScriptMetadata that are pure duplication — src/replay/__tests__/script.test.ts (589 lines, property-based) already covers both thoroughly.
3. ~1,820 lines re-testing runReplayScriptFile from session-replay-runtime.ts, which already has its own 540-line session-replay-runtime.test.ts (18 direct calls vs this file's 4).

Anyone auditing coverage for these modules lands in the wrong file or concludes coverage is missing. Note: PR #1451 (daemon modularity proposal) will eventually relocate replay tests wholesale — keep this move minimal and mechanical so it doesn't fight that migration.

Task

Redistribute the file's contents to where each test's subject lives; delete true duplicates.

Acceptance criteria

• The src/replay/vars.ts tests move to src/replay/__tests__/vars.test.ts (new file, co-located with its subject).
• The duplicated script.ts tests are deleted after a per-test check that an equivalent assertion exists in src/replay/__tests__/script.test.ts; any test asserting something script.test.ts does not cover moves there instead. List the disposition of each in the PR description (moved/deleted-as-duplicate-of-X).
• The runReplayScriptFile tests merge into session-replay-runtime.test.ts (or a clearly named sibling like session-replay-runtime-maestro.test.ts if size demands), deduplicating against its existing 18 call sites the same way — one obvious home for that function's coverage afterward.
• session-replay-vars.test.ts is deleted.
• No production changes; no net loss of distinct assertions (dedup of genuinely identical coverage is the only permitted reduction, and it must be itemized).
• pnpm test:unit green; changed-line coverage gate (check:coverage-changed) unaffected since no prod lines change.