Migrate harness from in-memory stores to CloudNativePG

Replace all in-memory Map-backed stores (credentials, models, agents,
tasks, iterations, usage) with Drizzle ORM queries against the
homelab-pg PostgreSQL cluster. All store functions are now async.

- Add 6 harness_* tables to @homelab/db schema
- Generate and apply initial Drizzle migration
- Add lazy DB connection proxy to avoid build-time errors
- Wire DATABASE_URL from sealed secret into harness deployment
- Update all API routes, orchestrator, executor, and boot to await
  async store operations

packages/db/src/schema.ts

@@ -1,4 +1,16 @@
-import { pgTable, serial, text, timestamp } from "drizzle-orm/pg-core";
+import {
+  pgTable,
+  serial,
+  text,
+  timestamp,
+  boolean,
+  integer,
+  real,
+  jsonb,
+  bigint,
+} from "drizzle-orm/pg-core";
+
+// ─── EXISTING ───────────────────────────────────────────────
 
 export const users = pgTable("users", {
   id: serial("id").primaryKey(),
@@ -7,3 +19,101 @@ export const users = pgTable("users", {
   createdAt: timestamp("created_at").defaultNow().notNull(),
   updatedAt: timestamp("updated_at").defaultNow().notNull(),
 });
+
+// ─── HARNESS: CREDENTIALS ──────────────────────────────────
+
+export const credentials = pgTable("harness_credentials", {
+  id: text("id").primaryKey(),
+  provider: text("provider").notNull(),
+  label: text("label").notNull(),
+  token: text("token").notNull(),
+  baseUrl: text("base_url"),
+  createdAt: timestamp("created_at").defaultNow().notNull(),
+  updatedAt: timestamp("updated_at").defaultNow().notNull(),
+});
+
+// ─── HARNESS: CURATED MODELS ───────────────────────────────
+
+export const curatedModels = pgTable("harness_curated_models", {
+  id: text("id").primaryKey(),
+  name: text("name").notNull(),
+  provider: text("provider").notNull(),
+  enabled: boolean("enabled").default(true).notNull(),
+  contextWindow: integer("context_window"),
+  costPer1kInput: real("cost_per_1k_input"),
+  costPer1kOutput: real("cost_per_1k_output"),
+  createdAt: timestamp("created_at").defaultNow().notNull(),
+  updatedAt: timestamp("updated_at").defaultNow().notNull(),
+});
+
+// ─── HARNESS: MODEL USAGE ──────────────────────────────────
+
+export const modelUsage = pgTable("harness_model_usage", {
+  id: serial("id").primaryKey(),
+  modelId: text("model_id").notNull(),
+  provider: text("provider").notNull(),
+  taskId: text("task_id").notNull(),
+  taskSlug: text("task_slug").notNull(),
+  iteration: integer("iteration").notNull(),
+  inputTokens: integer("input_tokens").notNull(),
+  outputTokens: integer("output_tokens").notNull(),
+  durationMs: integer("duration_ms").notNull(),
+  timestamp: bigint("timestamp", { mode: "number" }).notNull(),
+});
+
+// ─── HARNESS: AGENT CONFIGS ────────────────────────────────
+
+export const agentConfigs = pgTable("harness_agent_configs", {
+  id: text("id").primaryKey(),
+  name: text("name").notNull(),
+  runtime: text("runtime").notNull(), // "claude-code" | "codex" | "opencode"
+  modelId: text("model_id").notNull(),
+  provider: text("provider").notNull(),
+  maxTokens: integer("max_tokens"),
+  env: jsonb("env").$type<Record<string, string>>(),
+  createdAt: timestamp("created_at").defaultNow().notNull(),
+  updatedAt: timestamp("updated_at").defaultNow().notNull(),
+});
+
+// ─── HARNESS: TASKS ────────────────────────────────────────
+
+export const tasks = pgTable("harness_tasks", {
+  id: text("id").primaryKey(),
+  slug: text("slug").notNull(),
+  goal: text("goal").notNull(),
+  status: text("status").notNull().default("pending"), // pending | running | completed | failed
+  iteration: integer("iteration").notNull().default(0),
+  maxIterations: integer("max_iterations").notNull().default(6),
+  startedAt: bigint("started_at", { mode: "number" }),
+  completedAt: bigint("completed_at", { mode: "number" }),
+  project: text("project").notNull().default("—"),
+  evals: jsonb("evals").$type<Record<string, unknown>>().default({}).notNull(),
+  pr: jsonb("pr").$type<{ number: number; title: string; status: string }>(),
+  spec: jsonb("spec").$type<{
+    slug: string;
+    goal: string;
+    project: string;
+    agentId: string;
+    maxIterations: number;
+    criteria: { label: string; target: string }[];
+    constraints: string[];
+    knowledgeRefs: string[];
+  }>().notNull(),
+  createdAt: timestamp("created_at").defaultNow().notNull(),
+  updatedAt: timestamp("updated_at").defaultNow().notNull(),
+});
+
+// ─── HARNESS: ITERATIONS ───────────────────────────────────
+
+export const iterations = pgTable("harness_iterations", {
+  id: serial("id").primaryKey(),
+  taskId: text("task_id").notNull(),
+  n: integer("n").notNull(),
+  status: text("status").notNull().default("pending"), // pending | running | passed | failed
+  diagnosis: text("diagnosis"),
+  agentOutput: text("agent_output"),
+  evals: jsonb("evals").$type<Record<string, unknown>>(),
+  diffStats: text("diff_stats"),
+  startedAt: bigint("started_at", { mode: "number" }),
+  completedAt: bigint("completed_at", { mode: "number" }),
+});