docs backend evidence ev support EE 28

EE-28 — Bounded resource, coverage and failure benchmarks

Status: LOCAL_DONE (measured scope) Validation: PASS Integration: INTEGRATION_PENDING

Parent: 8ed7b1de (maintained dev, MEX-34). Date: 2026-10-23. Depends MEX-03 baselines, EE-27. Rules EV-08/20/23/24.

Measured now (this workstation, identified inputs)

• Rust prepare_charging on the pinned admitted OCM snapshot (/tmp/abastevo-ee04-snapshot/pois, 1,298 places / 2,089 groups):
  • cold build-independent run: 0.78 s wall, 15,080 KiB max RSS;
  • warm repeat: 0.66 s wall, 15,044 KiB max RSS;
  • artifacts: entities 3,331,857 B, decisions 1,602,082 B, manifest 164,730 B, aliases 0 B; byte-identical repeat.
  • Input 3,387 / accepted 3,387 / duplicates 0 / quarantined 0.
• Go/PostGIS public chain (TestEE27RustToPublicHTTPChain): 1.28 s total for fresh database migration, verified manifest load, atomic publication and full 13-page HTTP traversal of 1,298 places with 2,089 groups; coverage endpoint agrees. This is local test time, not production latency.
• Android search policy baseline remains the MEX-06 host measurement (indexed keystroke p95 0.35 ms vs 5.13 ms before) and OPT-A fixed 5-minute foreground call reduction (21→6 fresh, 21→0 offline). Those are prior measured artifacts, not re-run here and not EV-only.

Not measured / OWED

• Physical first-content, scroll/pagination frame time, cold/warm device cache, TalkBack and battery on a real Android device.
• Backend p95 under concurrent HTTP load and contention with safety/ private jobs; no load campaign against third parties.
• Disk-full/network-drop/process-kill campaigns beyond the targeted failure paths already covered by EE-27/MEX-33.

Limits

• No third-party load, no production measurements, no invented percentiles. Results are single-workstation local acceptance with the pinned source; they are not capacity or release certification.
• The simpler indexed/region-bounded design remains the fallback; no new caching service or job was introduced.

Next: EE-29/MEX-36/37 regression, privacy and final union.