feat(FN-2984): add droid CLI path reconciliation extension

The merge introduces a new droid CLI extension with path reconciliation across daemon, dashboard, and serve commands, along with supporting core and engine utilities. It also removes stale lint suppression comments (FN-2983). Tests cover the new CLI extension and path reconciliation logic.

Fusion-Task-Id: FN-2984

packages/core/src/__tests__/reconcile-droid-cli-paths.test.ts

@@ -0,0 +1,52 @@
+import { describe, it, expect } from "vitest";
+import { reconcileDroidCliPaths } from "../pi-extensions.js";
+
+const VENDORED = "/repo/packages/droid-cli/index.ts";
+const GLOBAL_NPM = "/opt/homebrew/lib/node_modules/droid-cli/index.ts";
+const PI_AGENT = "/Users/u/.pi/agent/extensions/droid-cli/index.ts";
+const UNRELATED = "/Users/u/.pi/agent/extensions/quota.ts";
+
+describe("reconcileDroidCliPaths", () => {
+  it("returns input unchanged when no vendored path is supplied", () => {
+    const input = [GLOBAL_NPM, UNRELATED];
+    expect(reconcileDroidCliPaths(input, null)).toEqual(input);
+  });
+
+  it("drops a globally-installed droid-cli and prepends the vendored path", () => {
+    const result = reconcileDroidCliPaths([GLOBAL_NPM, UNRELATED], VENDORED);
+    expect(result).toEqual([VENDORED, UNRELATED]);
+  });
+
+  it("drops droid-cli installed under .pi/agent/extensions/", () => {
+    const result = reconcileDroidCliPaths([PI_AGENT, UNRELATED], VENDORED);
+    expect(result).toEqual([VENDORED, UNRELATED]);
+  });
+
+  it("keeps the vendored path exactly once even if it appears in input", () => {
+    const result = reconcileDroidCliPaths(
+      [VENDORED, GLOBAL_NPM, UNRELATED],
+      VENDORED,
+    );
+    expect(result).toEqual([VENDORED, UNRELATED]);
+  });
+
+  it("preserves the relative order of unrelated extension paths", () => {
+    const a = "/ext/a.ts";
+    const b = "/ext/b.ts";
+    const c = "/ext/c.ts";
+    const result = reconcileDroidCliPaths([a, GLOBAL_NPM, b, c], VENDORED);
+    expect(result).toEqual([VENDORED, a, b, c]);
+  });
+
+  it("does not mistake substrings of droid-cli for the package", () => {
+    const looksLike = "/ext/some-droid-cli-helper/index.ts";
+    const result = reconcileDroidCliPaths([looksLike], VENDORED);
+    expect(result).toEqual([VENDORED, looksLike]);
+  });
+
+  it("matches case-insensitively (e.g. on macOS-cased filesystems)", () => {
+    const upper = "/opt/homebrew/lib/node_modules/DROID-CLI/index.ts";
+    const result = reconcileDroidCliPaths([upper], VENDORED);
+    expect(result).toEqual([VENDORED]);
+  });
+});

packages/core/src/index.ts

@@ -52,7 +52,7 @@ export { detectLegacyData, migrateFromLegacy, getMigrationStatus } from "./db-mi
 export { GlobalSettingsStore, resolveGlobalDir } from "./global-settings.js";
 export { isValidSqliteDatabaseFile } from "./sqlite-validation.js";
 export { DaemonTokenManager, DAEMON_TOKEN_PREFIX, DAEMON_TOKEN_HEX_LENGTH, isDaemonTokenFormat } from "./daemon-token.js";
-export { discoverPiExtensions, formatPiExtensionSource, getEnabledPiExtensionPaths, getFusionAgentDir, getFusionAgentSettingsPath, getLegacyPiAgentDir, getPiExtensionDiscoveryDirs, reconcileClaudeCliPaths, resolvePiExtensionProjectRoot, updatePiExtensionDisabledIds } from "./pi-extensions.js";
+export { discoverPiExtensions, formatPiExtensionSource, getEnabledPiExtensionPaths, getFusionAgentDir, getFusionAgentSettingsPath, getLegacyPiAgentDir, getPiExtensionDiscoveryDirs, reconcileClaudeCliPaths, reconcileDroidCliPaths, resolvePiExtensionProjectRoot, updatePiExtensionDisabledIds } from "./pi-extensions.js";
 export type { PiExtensionEntry, PiExtensionSettings, PiExtensionSource } from "./pi-extensions.js";
 export { canTransition, getValidTransitions, resolveDependencyOrder } from "./board.js";
 export { getTaskMergeBlocker, getTaskCompletionBlocker, isTaskReadyForMerge } from "./task-merge.js";

packages/core/src/pi-extensions.ts

@@ -276,6 +276,42 @@ export function reconcileClaudeCliPaths(
   return filtered;
 }
 
+/**
+ * Heuristic: does this extension path look like an external (non-Fusion)
+ * `droid-cli` install? We match any path with a directory segment named
+ * exactly `droid-cli`, except for the explicit vendored path that callers
+ * pass in (which always wins).
+ */
+function isExternalDroidCliPath(p: string, vendoredPath: string | null): boolean {
+  if (vendoredPath && p === vendoredPath) return false;
+  return /(^|[/\\])droid-cli([/\\]|$)/i.test(p);
+}
+
+/**
+ * Reconcile the assembled pi-extension load list so Fusion's vendored
+ * `@fusion/droid-cli` always wins over any externally-installed
+ * `droid-cli` (e.g. a stale `npm install -g droid-cli` left in
+ * `/opt/homebrew/lib/node_modules`, or `npm:droid-cli` in agent
+ * settings).
+ *
+ * Side-by-side loading of two extensions that register the same
+ * provider name (`droid-cli`) produces unpredictable winners
+ * depending on load order.
+ */
+export function reconcileDroidCliPaths(
+  paths: readonly string[],
+  vendoredPath: string | null,
+): string[] {
+  if (!vendoredPath) {
+    return [...paths];
+  }
+  const filtered = paths.filter((p) => !isExternalDroidCliPath(p, vendoredPath));
+  if (!filtered.includes(vendoredPath)) {
+    return [vendoredPath, ...filtered];
+  }
+  return filtered;
+}
+
 function getDisplayPathWithinRoot(root: string, targetPath: string): string | null {
   const usesWindowsPaths = /^[A-Za-z]:[\\/]/.test(root) || /^[A-Za-z]:[\\/]/.test(targetPath) || root.includes("\\") || targetPath.includes("\\");
   const pathApi = usesWindowsPaths ? win32 : { relative, isAbsolute, sep };