TASK-084: mark task Done in spec and milestone index

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Rkuh4aSmrD8m2f2vYqakb6

Author: etr

specs/tasks/M7-v2-cleanup/TASK-084.md

@@ -12,10 +12,10 @@ per-stdlib; only the ns/call constant is mono-platform. Capture the missing
 measurement so the TASK-039 ≥10× speedup gate has a real Linux baseline.
 
 **Action Items:**
-- [ ] On a representative Linux x86-64 host with libstdc++ (Ubuntu 22.04, the verify-build.yml default), run `bench_get_headers` against a clean v1 checkout (or via the existing v1-baseline harness). Capture median, p99, n.
-- [ ] Update `v1_constants.hpp:65-70` and `94-98` with the new libstdc++ value, separating it from the libc++ value.
-- [ ] Update `test/PERFORMANCE.md:34` with the per-stdlib table.
-- [ ] Re-run TASK-039's `≥10× speedup` assertion against the new baseline on the Linux lane and confirm it still passes.
+- [x] On a representative Linux x86-64 host with libstdc++ (Ubuntu 22.04, the verify-build.yml default), run `bench_get_headers` against a clean v1 checkout (or via the existing v1-baseline harness). Capture median, p99, n.
+- [x] Update `v1_constants.hpp:65-70` and `94-98` with the new libstdc++ value, separating it from the libc++ value.
+- [x] Update `test/PERFORMANCE.md:34` with the per-stdlib table.
+- [x] Re-run TASK-039's `≥10× speedup` assertion against the new baseline on the Linux lane and confirm it still passes.
 
 **Dependencies:**
 - Blocked by: TASK-039 (Done)
@@ -31,4 +31,4 @@ measurement so the TASK-039 ≥10× speedup gate has a real Linux baseline.
 **Related Requirements:** PRD §3.6 performance acceptance, PRD-REQ-REQ-001
 **Related Decisions:** None new
 
-**Status:** Backlog
+**Status:** Done

specs/tasks/M7-v2-cleanup/_index.md

@@ -48,7 +48,7 @@ TASK-093).
 | TASK-081 | Fill empty-on-correct-build unit suites and re-enable pthread leak detector | MED | M | Done |
 | TASK-082 | Tighten static-size bounds in `http_resource_test` and `webserver_pimpl_test` | MED | S | Done |
 | TASK-083 | Wire real CI gates into benchmarks | MED | M | Done |
-| TASK-084 | Re-measure libstdc++/Linux v1 baseline for `get_headers` ns/call | MED | S | Backlog |
+| TASK-084 | Re-measure libstdc++/Linux v1 baseline for `get_headers` ns/call | MED | S | Done |
 | TASK-085 | Residual test-smell sweep | MED | S | Backlog |
 | TASK-086 | Execute file-size split roadmap (FILE_LOC_MAX 750 → 500) | HIGH | L | Backlog |
 | TASK-087 | Restore msan CI lane | HIGH | M | Backlog |