update DEV_PLAN.md to reflect current status (128/130 tests passing)

seaweed-volume/DEV_PLAN.md

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+# Rust Volume Server — Dev Plan
+
+## Current Status (2026-03-07)
+
+**HTTP tests**: 54/55 pass (98.2%) — 1 unfixable: CONNECT method is a hyper/axum limitation
+**gRPC tests**: 74/75 pass (98.7%) — 1 Go-only: TestVolumeMoveHandlesInFlightWrites uses Go binaries exclusively
+**Total**: 128/130 (98.5%)
+**Rust unit tests**: 111 lib + 7 integration = 118
+
+## Completed Features
+
+All phases from the original plan are complete:
+
+- **Phase 1** — HTTP Core: CORS, OPTIONS, unsupported methods, static assets, path routing,
+  cookie validation, conditional headers, range requests, dedup 204, content-encoding,
+  readDeleted, chunk manifests, multipart validation, MD5 check, file size limit,
+  upload/download throttling, image resize/crop, download disposition
+- **Phase 2** — JWT/Security: signing keys from security.toml, token source precedence
+  (query > header > cookie), file_id claims, leeway=0
+- **Phase 3** — gRPC: maintenance mode, error message parity, ping routing, batch delete,
+  VolumeServerStatus, ReadVolumeFileStatus
+- **Phase 4** — Streaming gRPC: VolumeIncrementalCopy, CopyFile, ReceiveFile, ReadAllNeedles,
+  VolumeTailSender, VolumeCopy (partial), VacuumVolumeCheck
+- **Phase 5** — EC Shards: mount/unmount, delete, read, blob delete, rebuild, shards-to-volume,
+  copy, info
+- **Phase 6** — Advanced gRPC: ScrubVolume, ScrubEcVolume, Query, FetchAndWriteNeedle (stub),
+  VolumeTierMoveDat (error paths)
+- **Master Heartbeat** — Bidirectional streaming SendHeartbeat RPC, volume/EC registration,
+  leader changes, shutdown deregistration. Tested end-to-end with Go master.
+
+## Remaining Work (Production Readiness)
+
+These features are not covered by existing integration tests but are needed for
+production use in a full SeaweedFS cluster:
+
+### High Priority (needed for cluster operations)
+
+1. **VacuumVolumeCompact/Commit/Cleanup** — Volume compaction/garbage collection.
+   Without this, deleted space is never reclaimed. The master triggers this periodically.
+
+2. **VolumeCopy** — Full volume copy from peer. Currently stubbed. Needed for volume
+   rebalancing and migration between volume servers.
+
+3. **VolumeTailReceiver** — Live replication from source volume. Needed for volume moves
+   (copy + tail + switchover). Currently returns unimplemented.
+
+### Medium Priority (nice to have)
+
+4. **Remote Storage** — `FetchAndWriteNeedle` with actual remote backend support.
+   Currently returns "remote storage not configured". Needed only if using tiered storage.
+
+5. **VolumeTierMoveDatToRemote/FromRemote** — Move volume data to/from remote storage
+   backends (S3, etc.). Currently returns error paths only.
+
+### Low Priority
+
+6. **TestUnsupportedMethodConnectParity** — HTTP CONNECT method returns 400 in Go but
+   hyper rejects it before reaching the router. Would need a custom hyper service wrapper.
+
+## Test Commands
+
+```bash
+# Build
+cd seaweed-volume && cargo build --release
+
+# Run all Go integration tests with Rust volume server
+VOLUME_SERVER_IMPL=rust go test -v -count=1 -timeout 1200s ./test/volume_server/{grpc,http}/...
+
+# Run specific test
+VOLUME_SERVER_IMPL=rust go test -v -count=1 -timeout 60s -run "TestName" ./test/volume_server/http/...
+
+# Run Rust unit tests
+cd seaweed-volume && cargo test
+
+# Test heartbeat with Go master
+weed master -port=9333 &
+seaweed-volume --port 8080 --master localhost:9333 --dir /tmp/vol1 --max 7
+curl http://localhost:9333/dir/status  # should show Rust volume server registered
+```