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/drizzle/0004_cooing_black_knight.sql

@@ -0,0 +1,29 @@
+PRAGMA defer_foreign_keys=ON;
+--> statement-breakpoint
+CREATE TABLE `__new_federation_peers` (
+	`id` text PRIMARY KEY NOT NULL,
+	`origin` text NOT NULL,
+	`instance_name` text,
+	`hmac_secret` text NOT NULL,
+	`status` text DEFAULT 'active' NOT NULL,
+	`last_seen_at` integer,
+	`last_failure_at` integer,
+	`consecutive_failures` integer DEFAULT 0 NOT NULL,
+	`consecutive_auth_failures` integer DEFAULT 0 NOT NULL,
+	`last_synced_at` integer DEFAULT 0,
+	`remote_max_upload_size` integer,
+	`nonce_supported` integer DEFAULT 0 NOT NULL,
+	`pending_hmac_secret` text,
+	`secret_rotation_at` integer,
+	`secret_rotated_at` integer,
+	`auto_rotate_interval_days` integer DEFAULT 90 NOT NULL,
+	`created_at` integer NOT NULL
+);
+--> statement-breakpoint
+INSERT INTO `__new_federation_peers`("id", "origin", "instance_name", "hmac_secret", "status", "last_seen_at", "last_failure_at", "consecutive_failures", "consecutive_auth_failures", "last_synced_at", "remote_max_upload_size", "nonce_supported", "pending_hmac_secret", "secret_rotation_at", "secret_rotated_at", "auto_rotate_interval_days", "created_at") SELECT "id", "origin", "instance_name", "hmac_secret", "status", "last_seen_at", "last_failure_at", COALESCE("consecutive_failures", 0), "consecutive_auth_failures", "last_synced_at", "remote_max_upload_size", "nonce_supported", "pending_hmac_secret", "secret_rotation_at", "secret_rotated_at", "auto_rotate_interval_days", "created_at" FROM `federation_peers`;
+--> statement-breakpoint
+DROP TABLE `federation_peers`;
+--> statement-breakpoint
+ALTER TABLE `__new_federation_peers` RENAME TO `federation_peers`;
+--> statement-breakpoint
+CREATE UNIQUE INDEX `federation_peers_origin_unique` ON `federation_peers` (`origin`);

packages/server/drizzle/meta/_journal.json

@@ -29,6 +29,13 @@
       "when": 1776789567488,
       "tag": "0003_classy_loki",
       "breakpoints": true
+    },
+    {
+      "idx": 4,
+      "version": "6",
+      "when": 1776802580650,
+      "tag": "0004_cooing_black_knight",
+      "breakpoints": true
     }
   ]
 }