FN-5851: fix goal tool store resolution

Resolve goal tool lookups to the canonical project store from Fusion worktree directories.

- recognize both legacy .worktrees and .fusion/worktrees paths when resolving the project root for pi extensions
- add CLI coverage proving fn_goal_list and fn_goal_show return dashboard-created goals from a Fusion worktree cwd
- extend core worktree-resolution tests and keep the branch conflict recovery test worktree path isolated in tmpdir
- add a patch changeset for the published CLI fix

Files changed:
 .changeset/fn-5851-goal-store-resolution.md        |   5 +
 packages/cli/src/__tests__/goal-store-resolution.test.ts    | 104 +++++++++++++++++++++
 packages/core/src/__tests__/pi-extensions.test.ts  |  14 ++-
 packages/core/src/pi-extensions.ts                 |  12 ++-
 packages/engine/src/__tests__/branch-conflicts-recovery.test.ts    |   2 +-
 5 files changed, 130 insertions(+), 7 deletions(-)

Fusion-Task-Id: FN-5851

Fusion-Task-Lineage: ec4c8239-b953-4df7-9f72-02e17e4b0851

packages/core/src/__tests__/pi-extensions.test.ts

@@ -8,11 +8,15 @@ describe("getProjectRootFromWorktree", () => {
   it("detects POSIX worktree paths", () => {
     expect(getProjectRootFromWorktree("/repo/.worktrees/fn-001")).toBe("/repo");
     expect(getProjectRootFromWorktree("/repo/.worktrees/fn-001/src/file.ts")).toBe("/repo");
+    expect(getProjectRootFromWorktree("/repo/.fusion/worktrees/fn-001")).toBe("/repo");
+    expect(getProjectRootFromWorktree("/repo/.fusion/worktrees/fn-001/src/file.ts")).toBe("/repo");
   });
 
   it("detects Windows worktree paths", () => {
     expect(getProjectRootFromWorktree("C:\\repo\\.worktrees\\fn-001")).toBe("C:\\repo");
     expect(getProjectRootFromWorktree("C:\\repo\\.worktrees\\fn-001\\src\\file.ts")).toBe("C:\\repo");
+    expect(getProjectRootFromWorktree("C:\\repo\\.fusion\\worktrees\\fn-001")).toBe("C:\\repo");
+    expect(getProjectRootFromWorktree("C:\\repo\\.fusion\\worktrees\\fn-001\\src\\file.ts")).toBe("C:\\repo");
   });
 
   it("supports configured candidate worktrees dir paths", () => {
@@ -43,10 +47,14 @@ describe("resolvePiExtensionProjectRoot", () => {
     try {
       mkdirSync(join(root, ".fusion"), { recursive: true });
       mkdirSync(join(root, ".worktrees", "feature", ".fusion"), { recursive: true });
-      const cwd = join(root, ".worktrees", "feature", "sub");
-      mkdirSync(cwd, { recursive: true });
+      mkdirSync(join(root, ".fusion", "worktrees", "feature", ".fusion"), { recursive: true });
+      const legacyCwd = join(root, ".worktrees", "feature", "sub");
+      const fusionCwd = join(root, ".fusion", "worktrees", "feature", "sub");
+      mkdirSync(legacyCwd, { recursive: true });
+      mkdirSync(fusionCwd, { recursive: true });
 
-      expect(resolvePiExtensionProjectRoot(cwd)).toBe(root);
+      expect(resolvePiExtensionProjectRoot(legacyCwd)).toBe(root);
+      expect(resolvePiExtensionProjectRoot(fusionCwd)).toBe(root);
     } finally {
       rmSync(root, { recursive: true, force: true });
     }

packages/core/src/pi-extensions.ts

@@ -40,9 +40,15 @@ export function getProjectRootFromWorktree(
   cwd: string,
   opts?: { worktreesDirCandidates?: string[] },
 ): string | null {
-  const legacyMatch = cwd.match(/^(.+?)[\\/]\.worktrees[\\/][^\\/]+(?:[\\/]|$)/);
-  if (legacyMatch) {
-    return legacyMatch[1]!;
+  const knownWorktreePatterns = [
+    /^(.+?)[\\/]\.worktrees[\\/][^\\/]+(?:[\\/]|$)/,
+    /^(.+?)[\\/]\.fusion[\\/]worktrees[\\/][^\\/]+(?:[\\/]|$)/,
+  ];
+  for (const pattern of knownWorktreePatterns) {
+    const match = cwd.match(pattern);
+    if (match) {
+      return match[1]!;
+    }
   }
 
   for (const candidate of opts?.worktreesDirCandidates ?? []) {