Add a runnable dev environment, and fix the pins that stopped it booting

The edge route had never been run. Adding a way to run it turned up that the
server could not start at all, for two independent dependency reasons that
typechecking could not see:

- `elysia: ^1.1.26` had resolved to 1.4.30, which calls `t.Module` - a TypeBox
  0.34 API - while this repo pinned TypeBox 0.33. `t.Module is not a function`.
- `drizzle-typebox: ^0.2.1` resolved to a version whose peers demand
  `drizzle-orm >= 0.36`, against the `^0.33.0` pinned here. Importing it threw
  `Export named 'getViewSelectedFields' not found`.

Both are caret ranges that drifted into combinations nobody chose. elysia,
@sinclair/typebox and the drizzle packages are now pinned tightly, TypeBox
forward to 0.34.52 (which satisfies Elysia and drizzle-typebox 0.1.1 alike),
and tests/dependency_identity.test.ts fails if the TypeBox version ever differs
between here and @continuum/ts-types - the skew that made every shared schema
invalid, with an error message pointing at Standard Schema instead.

Dropping to drizzle-typebox 0.1.1 widens `jsonb` in the generated validators,
so `metadata` needs an explicit object shape in validators.ts; the column is
declared `$type<Record<string, unknown>>()` and a validated body otherwise is
not assignable to `.values()`.

scripts/:

- `install-docker.sh` - one-time host setup, kept separate because it touches
  the machine rather than containers.
- `dev-env.sh up|down|reset|status|psql|schema|env` - Valkey + Postgres/pgvector.
  Uses docker-compose.yml when a daemon answers, and otherwise runs the same two
  services from apt. That fallback is not hypothetical: Docker cannot run in this
  sandbox at all. dockerd needs CAP_NET_ADMIN to build its bridge; with
  `--bridge=none --iptables=false` it starts but cannot unpack an image without
  CAP_SYS_ADMIN; with `--storage-driver=vfs` it still fails because registering a
  layer needs user namespaces, which are blocked outright. All three are
  host-level grants, so no script can work around them - hence a second path
  rather than a broken first one.
- `e2e-edge.sh` - the test the unit tests cannot be. Seeds a farm, claims its
  printers, mints an edge token, runs the real continuum-proxy, and asserts live
  telemetry reached Postgres and a command reached a printer. It only sends a fan
  speed, only to a printer reporting IDLE, and puts it back afterwards.
- `capture-gateway-frames.js` - records what a gateway really sends, for
  refreshing tests/fixtures/. Read-only unless FAN_TEST_PRINTER is set. The test
  comment referred to this before it existed.

Verified end to end, from a dropped and freshly migrated database: `h2c`
persisted as printing/RUNNING 22% layer 2/25 nozzle 230 bed 35 with 3 HMS
alerts, `p1p` as idle/IDLE, and `POST /printers/:id/commands` reached the P1P's
fan and came back ok:true. An unclaimed printer is refused 409
PRINTER_UNREACHABLE rather than guessed at.

Two things the e2e script got wrong first, both now fixed in it: it waited for
the first printer row instead of all of them, which silently tested only the v2
printer (a v1 Bambu reports one tick later); and `$!` after `( cd ... ) &` is
the subshell, so cleanup left an orphaned gateway reconnecting with a token for
a deleted farm and polluting the next run.

Note: `drizzle/` is gitignored, so the generated migration is not committed and
there is no migration history in the repo. Left as-is deliberately - that is a
workflow call, flagged in PLAN.md.

src/routes/ws/edge.ts

@@ -307,7 +307,10 @@ export const edgeWsRoute = new Elysia()
           }
           clearTimeout(pending.timer);
           conn.pending.delete(message.command_id);
-          pending.resolve({ ok: message.ok, error: message.error });
+          // `?? undefined` because the wire allows either absent or null for
+          // "no error" (see the Maybe() helper in @continuum/ts-types) and
+          // callers should only have to check one of them.
+          pending.resolve({ ok: message.ok, error: message.error ?? undefined });
           break;
         }