perf(web): reuse work log rows during streaming - #8006

💭 I'm checking whether session-logic.ts in apps/web is Effect service code, since the PR introduces a module-global WeakMap cache keyed by a Symbol, which raises questions about Effect conventions and potential mutation issues. I want to inspect the file directly to confirm.

1. browse_code — apps/web/src/session-logic.ts

2. git_tools — b1670ac..647e760

💭 This PR is actually a pure UI derivation function, not Effect service code, so the module-global dependency-hiding rule doesn't really apply here since there's no Effect service being created or refactored, and the imports remain correctly unchanged. Since there are no findings within scope, I should respond with "All clear" — though I need to reconcile that instruction with the requirement for valid JSON output, so I'll set the summary field to "All clear" and mark the state as success, since the check defaults to failure only when there are actual findings.