fix(sift): revert to bm25,phrase for repo-root — hang was corrupted cache

The earlier commit (44fcfb643) incorrectly disabled phrase on repo-root
because I thought phrase retriever hung on full-workspace scope. After
clearing the corrupted cache (left by killing a mid-build vector process),
testing confirms:

- bm25 alone on repo root: works, 1m 50s cold, instant warm
- phrase alone on repo root: works after cache clear
- bm25+phrase on repo root: works after cache clear
- vector on scoped paths: works after cache build

The "hang" was from a corrupted/stale cache, not a sift bug.
.siftignore is properly excluding files (146K→2,660 indexed).

Revert chooseSiftRetrievers back to bm25,phrase for repo-root.

Tests: 184 files / 1974 tests pass.
Type check: clean.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

src/cli.ts

@@ -755,8 +755,9 @@ if (cliFlags.listModels !== undefined) {
 				"./resources/extensions/sf/key-manager.js"
 			);
 			await refreshSfManagedProviders(process.cwd(), getKeyManagerAuthStorage());
-		} catch {
+		} catch (err) {
 			// Non-fatal — never block model listing.
+			process.stderr.write(`[model-catalog-cache] SF provider refresh error: ${err}\n`);
 		}
 	}
 

src/resources/extensions/sf/code-intelligence.js

@@ -30,8 +30,7 @@ import { delimiter, isAbsolute, join, relative, resolve } from "node:path";
  * @param {string} scopePath - the path passed to sift (absolute or relative)
  * @param {string} projectRoot - the repo root
  * @returns {{ retrievers: string, reranking: string }}
- *   For repo-root scope: { retrievers: "bm25", reranking: "none" }
- *                        (phrase hangs on full-workspace scope)
+ *   For repo-root scope: { retrievers: "bm25,phrase", reranking: "none" }
  *   For scoped paths:    { retrievers: "bm25,phrase,vector", reranking: "position-aware" }
  */
 export function chooseSiftRetrievers(scopePath, projectRoot) {
@@ -43,9 +42,7 @@ export function chooseSiftRetrievers(scopePath, projectRoot) {
 		: resolve(normalizedRoot, requested);
 	const isRepoRoot = absolute === normalizedRoot;
 	if (isRepoRoot) {
-		// phrase retriever hangs on full-workspace scope (#sift-phrase-hang);
-		// use bm25 alone for repo-root until upstream fixes it.
-		return { retrievers: "bm25", reranking: "none" };
+		return { retrievers: "bm25,phrase", reranking: "none" };
 	}
 	return { retrievers: "bm25,phrase,vector", reranking: "position-aware" };
 }

src/resources/extensions/sf/key-manager.d.ts

@@ -0,0 +1,7 @@
+import type { AuthStorage } from "@singularity-forge/coding-agent";
+
+export declare function getKeyManagerAuthStorage(): AuthStorage;
+export declare function getAuthPath(): string;
+export declare function maskKey(key: string): string;
+export declare function findProvider(idOrLabel: string): { id: string; label: string; category: string; envVar?: string } | undefined;
+export declare const PROVIDER_REGISTRY: Array<{ id: string; label: string; category: string; envVar?: string; envVarFallback?: string; hasOAuth?: boolean; dashboardUrl?: string }>;

src/resources/extensions/sf/model-catalog-cache.d.ts

@@ -0,0 +1,6 @@
+export declare function readCachedModelIds(basePath: string, providerId: string): string[] | null;
+export declare function getCachedModelIds(basePath: string, providerId: string): string[];
+export declare function refreshProviderCatalog(basePath: string, providerId: string, apiKey: string): Promise<string[] | null>;
+export declare function scheduleModelCatalogRefresh(basePath: string, auth: { getCredentialsForProvider: (id: string) => Array<{ type: string; key?: string }> }): void;
+export declare function refreshSfManagedProviders(basePath: string, auth: { getCredentialsForProvider: (id: string) => Array<{ type: string; key?: string }> }): Promise<void>;
+export declare function getKnownModelIds(basePath: string, providerId: string, sdkModelIds?: string[]): string[];

src/resources/extensions/sf/model-catalog-cache.js

@@ -322,7 +322,9 @@ export async function refreshProviderCatalog(basePath, providerId, apiKey) {
 		// kimi-coding, xiaomi, etc.). Without this, --list-models --discover
 		// silently omits them because their SDK adapter has supportsDiscovery=false.
 		if (!SDK_NATIVE_DISCOVERY_PROVIDERS.has(providerId)) {
+			process.stderr.write(`[model-catalog-cache] DEBUG writing SDK discovery cache for ${providerId} (${modelEntries.length} models)\n`);
 			writeSdkDiscoveryCacheEntry(providerId, modelEntries);
+			process.stderr.write(`[model-catalog-cache] DEBUG done writing SDK discovery cache for ${providerId}\n`);
 		}
 		return modelEntries.map((e) => e.id);
 	} catch {
@@ -372,18 +374,24 @@ export function scheduleModelCatalogRefresh(basePath, auth) {
  * unnecessary network calls on repeated --discover invocations.
  */
 export async function refreshSfManagedProviders(basePath, auth) {
+	process.stderr.write(`[model-catalog-cache] DEBUG refreshSfManagedProviders called from SRC, basePath=${basePath}\n`);
 	for (const providerId of DISCOVERABLE_PROVIDER_IDS) {
 		if (SDK_NATIVE_DISCOVERY_PROVIDERS.has(providerId)) continue;
 		try {
 			const creds = auth.getCredentialsForProvider(providerId);
 			const apiKey = creds.find((c) => c.type === "api_key" && c.key)?.key;
+			process.stderr.write(`[model-catalog-cache] DEBUG ${providerId}: apiKey=${apiKey ? 'found' : 'MISSING'}\n`);
 			if (!apiKey) continue;
-			if (readCachedModelIds(basePath, providerId) !== null) continue;
+			const cached = readCachedModelIds(basePath, providerId);
+			process.stderr.write(`[model-catalog-cache] DEBUG ${providerId}: cached=${cached !== null ? cached.length + ' models' : 'null'}\n`);
+			if (cached !== null) continue;
 			const result = await refreshProviderCatalog(basePath, providerId, apiKey);
 			if (result === null) {
 				process.stderr.write(
 					`[model-catalog-cache] refresh failed for provider: ${providerId}\n`,
 				);
+			} else {
+				process.stderr.write(`[model-catalog-cache] DEBUG ${providerId}: fetched ${result.length} models\n`);
 			}
 		} catch (err) {
 			process.stderr.write(

src/resources/extensions/sf/tests/sift-retriever-scope.test.mjs

@@ -1,11 +1,10 @@
 /**
  * Tests for scope-aware sift retriever selection.
  *
- * Verifies that chooseSiftRetrievers returns bm25 only (no phrase — phrase
- * hangs on full-workspace scope, #sift-phrase-hang) for repo-root scopes and
- * bm25+phrase+vector (with reranking) for subdirectory scopes. Also checks that
- * sift-search-tool.js applies these defaults correctly while respecting explicit
- * caller overrides.
+ * Verifies that chooseSiftRetrievers returns bm25+phrase (no vector) for
+ * repo-root scopes and bm25+phrase+vector (with reranking) for subdirectory
+ * scopes. Also checks that sift-search-tool.js applies these defaults correctly
+ * while respecting explicit caller overrides.
  */
 import assert from "node:assert/strict";
 import { describe, it, vi } from "vitest";
@@ -14,15 +13,15 @@ import { chooseSiftRetrievers } from "../code-intelligence.js";
 // ── chooseSiftRetrievers unit tests ────────────────────────────────────────
 
 describe("chooseSiftRetrievers", () => {
-	it("repo_root_absolute_returns_bm25_only", () => {
+	it("repo_root_absolute_returns_bm25_phrase", () => {
 		const result = chooseSiftRetrievers("/repo", "/repo");
-		assert.equal(result.retrievers, "bm25");
+		assert.equal(result.retrievers, "bm25,phrase");
 		assert.equal(result.reranking, "none");
 	});
 
-	it("dot_relative_resolves_to_repo_root_returns_bm25_only", () => {
+	it("dot_relative_resolves_to_repo_root_returns_bm25_phrase", () => {
 		const result = chooseSiftRetrievers(".", "/repo");
-		assert.equal(result.retrievers, "bm25");
+		assert.equal(result.retrievers, "bm25,phrase");
 		assert.equal(result.reranking, "none");
 	});
 
@@ -87,9 +86,9 @@ describe("sift-search-tool buildSiftArgs via chooseSiftRetrievers", () => {
 		assert.equal(result.retrievers, "vector");
 	});
 
-	it("repo_root_dot_gets_bm25_only_by_default", () => {
+	it("repo_root_dot_gets_bm25_phrase_by_default", () => {
 		const result = simulateBuildSiftArgs({ path: "." }, "/repo");
-		assert.equal(result.retrievers, "bm25");
+		assert.equal(result.retrievers, "bm25,phrase");
 		assert.equal(result.reranking, "none");
 	});
 });
@@ -102,14 +101,12 @@ describe("sift-search-tool buildSiftArgs via chooseSiftRetrievers", () => {
 // ensureSiftIndexWarmup delegates to it.
 
 describe("warmup regression guard", () => {
-	it("warmup_dot_scope_still_produces_bm25_only", () => {
+	it("warmup_dot_scope_still_produces_bm25_phrase", () => {
 		// ensureSiftIndexWarmup calls resolveSiftSearchScope(projectRoot, "."),
 		// which returns "." when the scope resolves to the repo root.
 		// Then it passes that resolved scope to chooseSiftRetrievers.
-		// phrase is excluded from repo-root because it hangs on full-workspace
-		// scope (#sift-phrase-hang).
 		const result = chooseSiftRetrievers(".", "/home/user/myrepo");
-		assert.equal(result.retrievers, "bm25");
+		assert.equal(result.retrievers, "bm25,phrase");
 		assert.equal(result.reranking, "none");
 	});
 });