fix(ai): migrated model cache schema v2 rows

Added a model-cache migration that backfills the schema v3 static_fingerprint column and preserves v2 cached provider discovery rows. Added regression coverage for reading legacy cache data and overwriting it on the next discovery write.\n\nFixes #1219

packages/ai/CHANGELOG.md

@@ -5,6 +5,7 @@
 ### Fixed
 
 - Fixed DeepSeek V4 direct API requests with tools to keep documented thinking mode instead of dropping reasoning: lower OMP efforts now map to DeepSeek's supported `high`, `tool_choice` is omitted, `thinking: { type: "enabled" }` and `max_tokens` are sent, and partial user `reasoningEffortMap` overrides merge with DeepSeek defaults. ([#1207](https://github.com/can1357/oh-my-pi/issues/1207))
+- Fixed model cache schema v2 databases so offline refreshes preserve cached provider discoveries after upgrading to schema v3 and subsequent online refreshes can overwrite the cache. ([#1219](https://github.com/can1357/oh-my-pi/issues/1219))
 
 ## [15.1.7] - 2026-05-19
 ### Added

packages/ai/src/model-cache.ts

@@ -17,6 +17,10 @@ interface CacheRow {
 	models: string;
 }
 
+interface TableInfoRow {
+	name: string;
+}
+
 interface CacheEntry<TApi extends Api = Api> {
 	models: Model<TApi>[];
 	fresh: boolean;
@@ -55,11 +59,21 @@ function getDb(dbPath?: string): Database {
 			models TEXT NOT NULL
 		)
 	`);
+	migrateCacheSchema(db);
+
 	sharedDb = db;
 	sharedDbPath = resolvedPath;
 	return db;
 }
 
+function migrateCacheSchema(db: Database): void {
+	const columns = db.prepare("PRAGMA table_info(model_cache)").all() as TableInfoRow[];
+	if (!columns.some(column => column.name === "static_fingerprint")) {
+		db.run("ALTER TABLE model_cache ADD COLUMN static_fingerprint TEXT NOT NULL DEFAULT ''");
+	}
+	db.run("UPDATE model_cache SET version = ? WHERE version = 2", [CACHE_SCHEMA_VERSION]);
+}
+
 export function readModelCache<TApi extends Api>(
 	providerId: string,
 	ttlMs: number,

packages/ai/test/model-cache.test.ts

@@ -0,0 +1,77 @@
+import { Database } from "bun:sqlite";
+import { afterEach, beforeEach, describe, expect, it } from "bun:test";
+import * as fs from "node:fs/promises";
+import * as os from "node:os";
+import * as path from "node:path";
+import { readModelCache, writeModelCache } from "../src/model-cache";
+import type { Model } from "../src/types";
+
+const TTL_MS = 24 * 60 * 60 * 1000;
+
+function createModel(id: string, name: string): Model<"openai-completions"> {
+	return {
+		id,
+		name,
+		api: "openai-completions",
+		provider: "ollama-cloud",
+		baseUrl: "https://ollama.com/v1",
+		reasoning: false,
+		input: ["text"],
+		cost: {
+			input: 0,
+			output: 0,
+			cacheRead: 0,
+			cacheWrite: 0,
+		},
+		contextWindow: 4096,
+		maxTokens: 1024,
+	};
+}
+
+describe("model cache migrations", () => {
+	let tempDir = "";
+	let dbPath = "";
+
+	beforeEach(async () => {
+		tempDir = await fs.mkdtemp(path.join(os.tmpdir(), "pi-ai-model-cache-"));
+		dbPath = path.join(tempDir, "models.db");
+	});
+
+	afterEach(async () => {
+		if (tempDir) {
+			await fs.rm(tempDir, { recursive: true, force: true });
+			tempDir = "";
+			dbPath = "";
+		}
+	});
+
+	it("preserves v2 cached models and lets the next discovery overwrite them", () => {
+		const legacyModel = createModel("legacy-cloud-model", "Legacy Cloud Model");
+		const legacyDb = new Database(dbPath, { create: true });
+		legacyDb.run(`
+			CREATE TABLE model_cache (
+				provider_id TEXT PRIMARY KEY,
+				version INTEGER NOT NULL,
+				updated_at INTEGER NOT NULL,
+				authoritative INTEGER NOT NULL DEFAULT 0,
+				models TEXT NOT NULL
+			)
+		`);
+		legacyDb.run(
+			"INSERT INTO model_cache (provider_id, version, updated_at, authoritative, models) VALUES (?, ?, ?, ?, ?)",
+			["ollama-cloud", 2, Date.now(), 1, JSON.stringify([legacyModel])],
+		);
+		legacyDb.close();
+
+		const migrated = readModelCache<"openai-completions">("ollama-cloud", TTL_MS, Date.now, dbPath);
+		expect(migrated?.models.map(model => model.id)).toEqual(["legacy-cloud-model"]);
+		expect(migrated?.staticFingerprint).toBe("");
+
+		const replacementModel = createModel("fresh-cloud-model", "Fresh Cloud Model");
+		writeModelCache("ollama-cloud", Date.now(), [replacementModel], true, "static-v3", dbPath);
+
+		const overwritten = readModelCache<"openai-completions">("ollama-cloud", TTL_MS, Date.now, dbPath);
+		expect(overwritten?.models.map(model => model.id)).toEqual(["fresh-cloud-model"]);
+		expect(overwritten?.staticFingerprint).toBe("static-v3");
+	});
+});