fix: call resolve_forge_remote before formula_worktree_setup in supervisor-run.sh (implements #1120) (#1121)

Make formula_worktree_setup() self-heal: if FORGE_REMOTE is unset, call
resolve_forge_remote() automatically. This eliminates the class of bug
where a caller forgets the precondition, rather than patching one caller.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

lib/formula-session.sh

@@ -792,10 +792,13 @@ build_sdk_prompt_footer() {
 # Creates an isolated worktree for synchronous formula execution.
 # Fetches primary branch, cleans stale worktree, creates new one, and
 # sets an EXIT trap for cleanup.
-# Requires globals: PROJECT_REPO_ROOT, PRIMARY_BRANCH, FORGE_REMOTE.
-# Ensure resolve_forge_remote() is called before this function.
+# Requires globals: PROJECT_REPO_ROOT, PRIMARY_BRANCH.
+# Calls resolve_forge_remote() automatically if FORGE_REMOTE is unset.
 formula_worktree_setup() {
   local worktree="$1"
+  if [ -z "${FORGE_REMOTE:-}" ]; then
+    resolve_forge_remote
+  fi
   cd "$PROJECT_REPO_ROOT" || return
   git fetch "${FORGE_REMOTE}" "$PRIMARY_BRANCH" 2>/dev/null || true
   worktree_cleanup "$worktree"