fix: resume selection under-reports task totals with multiple loops

The resume prompt counted total/completed from progress.tasks, which only
records TOUCHED tasks (started/completed/failed) — never-started tasks were
silently missing, and file-checkbox completions weren't counted unless
markCompleted had run. With e.g. 10 tasks where 3 completed and 5 untouched,
it showed 3/5 done instead of 3/10 done.

- add countPRDResumeStats (src/utils.ts): total from parseTaskFile of the
  PRD source; completed = progress completions ∪ PRD checkbox completions,
  deduped by task id; failed from progress. Falls back to touched-task
  counts when the source file is missing/unparseable.
- selectPRDToResume (index.ts) uses the helper instead of Object.keys().
- tests/resume-stats.test.ts: 4 regression tests.

Includes pre-existing uncommitted changes: index.ts tab-reformat (matches
src/ style) and package.json version bump 0.4.2 -> 0.4.3.

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@mikefreno/ralpi",
-  "version": "0.4.2",
+  "version": "0.4.3",
   "description": "Execute tasks from task files/PRD's using DAG-based dependency resolution with persistent progress tracking",
   "keywords": [
     "pi-package",