feat(db): Redis and MinIO snapshot/restore dumpers (spec 15)

[gustavobertoi]

What

Extends the spec-15 db snapshot/db restore data-lifecycle verbs beyond Postgres to the other stateful shared engines, behind the existing internal/db Dumper seam. Today only Postgres has a dumper; this adds Redis and MinIO and wires engine selection.

RedisDumper (internal/db/redis.go)

• Shells redis-cli behind the injectable Runner (mirrors PgDumper).
• Snapshot: redis-cli --rdb <out> — a whole-instance RDB via replication SYNC; does not stop the shared server, so other tenants are undisturbed.
• Restore: streams the artifact back through redis-cli's mass-insert pipe (sh -c "redis-cli … --pipe < dump", because the shared Runner has no stdin channel). Never restarts/bounces the container.
• Password rides REDISCLI_AUTH in the process env, never on argv. Preflight degrades the db verbs only, with a one-line redis-cli not found remediation.
• Best-effort (documented): a host client cannot cheaply carve one logical DB out of a live shared Redis, and a byte-faithful whole-RDB reload needs a controlled restart the never-recreate guard forbids. Redis is exactly the engine spec 15 flags as best-effort for the shared model.

MinioDumper (internal/db/minio.go)

• Uses the already-vendored pure-Go aws-sdk-go-v2 S3 client (no new external binary) behind an S3Factory seam.
• Snapshot: list + get the tenant bucket's objects into a deterministic (key-sorted) tar under the content-addressed store. Only the tenant bucket is read → project A can never capture project B.
• Restore: read the tar, put each object back into the same bucket (bucket names are globally unique per instance).

Wiring (internal/orchestrate/snapshot.go, internal/cli/db.go)

• resolveTenant now derives the per-engine tenant namespace (pg db / redis index / minio bucket); tenantConn builds the right ConnInfo (redis auth-less by default); SelectDumper returns the correct dumper by --kind.
• Dump file extension + SnapshotMeta.Kind follow the engine (.dump/.rdb/.tar).
• db snapshot/db restore gain --kind pg|redis|minio.
• Host-port overlay reachability pattern and lock-first ledger writes are unchanged (streaming outside the flock, row writes inside).

Why

Redis/MinIO tenants deserve the same per-project snapshot/restore lifecycle as Postgres; the Dumper seam was designed for exactly this extension.

How tested

CGO_ENABLED=1 go test ./internal/... (+ -race on db/orchestrate/cli) all green; CGO_ENABLED=0 go build ./..., go vet ./..., gofmt -l clean.

• Redis: snapshot/restore argv + auth-in-env-not-argv + no-auth/no-index cases + IsEmpty via mock runner.
• MinIO: snapshot/restore round-trip, determinism, tenant isolation, IsEmpty via a mock in-memory S3.
• Dumper-selection-by-engine; full-flow redis/minio Snapshot/Restore over the host-port overlay with the mock docker client.

No changes to internal/generate or templates/, so generated-artifact determinism is unaffected.

🤖 Generated with Claude Code