fix(schema): normalize federation_peers.consecutive_failures to NOT NULL

The column was `integer DEFAULT 0` (nullable) since the initial schema.
Counters should not be nullable — the semantics are a count, not an
optional measurement. `consecutive_auth_failures` (added later) was
correctly declared NOT NULL; tightening `consecutive_failures` to match
removes the drift and eliminates the "|null" burden everywhere the value
is read.

SQLite does not support in-place ALTER … SET NOT NULL, so drizzle-kit
cannot auto-generate this. The manual migration uses the standard
SQLite recreate pattern (new table + INSERT SELECT + DROP + RENAME +
recreate index) under `PRAGMA defer_foreign_keys = ON` so the existing
federation_outbox → federation_peers FK survives the swap. The COPY
step coalesces any hypothetical NULL to 0 defensively; live probes on
both test instances (nova, orbit) showed zero NULL rows so no
actual backfill is required.

Verified by applying the full migration chain against a copy of the VM's
live DB: column ends as `notnull=1 dflt=0`, the peer row is preserved,
the unique index on origin is recreated, NULL inserts are rejected, and
`PRAGMA foreign_key_check` reports no violations.

Server `SanitizedPeer.consecutiveFailures` tightened to `number` to
match the new drizzle inference and the shared `FederationPeer` shape.

Follow-up #22 from S2S DM unification backlog.

packages/server/src/db/schema.ts

@@ -362,7 +362,7 @@ export const federationPeers = sqliteTable('federation_peers', {
   status: text('status').notNull().default('active'),
   lastSeenAt: integer('last_seen_at'),
   lastFailureAt: integer('last_failure_at'),
-  consecutiveFailures: integer('consecutive_failures').default(0),
+  consecutiveFailures: integer('consecutive_failures').notNull().default(0),
   consecutiveAuthFailures: integer('consecutive_auth_failures').notNull().default(0),
   lastSyncedAt: integer('last_synced_at').default(0),
   remoteMaxUploadSize: integer('remote_max_upload_size'),

packages/server/src/routes/federation.ts

@@ -27,7 +27,7 @@ interface SanitizedPeer {
   status: string;
   lastSeenAt: number | null;
   lastFailureAt: number | null;
-  consecutiveFailures: number | null;
+  consecutiveFailures: number;
   lastSyncedAt: number | null;
   createdAt: number;
   rotationInProgress: boolean;