ROADMAP/spec: archive H3 spec (Phase 3 done end-to-end)

`map-h3-shard-rearchitecture.md` → `specs/done/`. All three
phases complete:
- Phase 1 (`a965131` etc.): pipeline + manifest carry-overs.
- Phase 2 (`24a4d91` etc.): viewport-aware client picker.
- Phase 3 (`52ec2653a40`, `55cc13ba1f2`, `d9c8346ce4a`):
  v1 layout fully removed (FE fetch path, BE outputs, S3
  keys deleted via `aws s3 sync --delete`).

ROADMAP BE #3 marked done; date stamp bumped to 2026-04-28.

Author: ryan-williams

specs/ROADMAP.md

@@ -3,7 +3,7 @@
 Living doc capturing relative priority across open specs. Update as
 priorities shift; treat as a default ordering, not a contract.
 
-## Active sequence (2026-04-27)
+## Active sequence (2026-04-28)
 
 User-confirmed ordering. `e` and laptop work in parallel; nothing is
 gating the other today.
@@ -18,10 +18,12 @@ gating the other today.
    between NJSP and NJDOT fatal crashes (currently ~93%
    coverage). Foundational for crash-detail enrichment +
    reconciled annual totals.
-3. **Map v2 Phase 3 (BE half)** — drop v1 outputs from
-   `map.dvc`; `map_sync.dvc` clears stale S3 keys via
-   `aws s3 sync --delete`. Should land *after* the FE half
-   deploys to CFP so no stale client hits 404s.
+3. ~~**Map v2 Phase 3 (BE half)**~~ — done. `map.dvc` cmd
+   rewritten to drop v1 outputs (`55cc13ba1f2`); local
+   re-run shrunk `map/` 377MB → 127MB. CFP redeployed
+   (`d9c8346ce4a`); `map_sync.dvc` ran `aws s3 sync --delete`
+   so v1 S3 keys are gone (`manifest.json`, `by-year/`,
+   `by-year-county/`, `hex-r{7,8}/` all return 404).
 
 ### Frontend (laptop)
 

specs/map-h3-shard-rearchitecture.md specs/done/map-h3-shard-rearchitecture.mdspecs/map-h3-shard-rearchitecture.md renamed to specs/done/map-h3-shard-rearchitecture.md

@@ -3,15 +3,15 @@
 > Status:
 > - Phase 1 (pipeline): **done**. `njdot export_map_v2` generates `www/public/njdot/map/v2/` alongside the v1 tree; `map.dvc` cmd extended.
 > - Phase 2 (client viewport-aware shard picker): **done**. `pickFetchPlanV2` in `www/src/map/v2.ts` returns `FetchPlan = points|hex(res)`; viewport-keyed shard cache; year-range row-group pushdown; r6 single-file fallback when shard count >30; `dataKind` plumbed through `useCrashData`; `CrashFilter.scale` removed from public type.
-> - Phase 3 (drop v1): in progress.
->   - FE half **done** (`52ec2653a40`). v1 fetch path removed from
+> - Phase 3 (drop v1): **done** end-to-end (2026-04-28).
+>   - FE half (`52ec2653a40`): v1 fetch path removed from
 >     `useCrashData.ts`; `pickFetchPlanV2` viewport optional with r6
 >     single-file fallback; v2 always-on (`?v2=1` flag deleted).
->   - BE half: `map.dvc` cmd updated to drop v1 outputs (`by-year/`,
->     `by-year-county/`, `hex-r7/`, `hex-r8/`, `manifest.json`) and
->     re-run locally (377MB → 127MB, 660 files). Remaining: push so
->     CFP deploys FE, then run `map_sync.dvc` (`aws s3 sync --delete`)
->     to clean stale S3 keys.
+>   - BE half (`55cc13ba1f2`, `d9c8346ce4a`): `map.dvc` cmd dropped v1
+>     outputs (`by-year/`, `by-year-county/`, `hex-r7/`, `hex-r8/`,
+>     `manifest.json`); local re-run shrunk `map/` 377MB → 127MB.
+>     CFP redeployed; `map_sync.dvc` ran `aws s3 sync --delete` so
+>     v1 S3 keys return 404.
 
 ## Motivation