feat(dev-fkeys): propagate prefix-arg to projectile through F4 / F6

I had four call sites passing literal nil to `projectile-compile-project' / `projectile-run-project' / `projectile-test-project'. The literal nil ignored whatever prefix arg the user gave. So `C-u F4 → Compile' or `C-u F6 → All tests' didn't actually force projectile's re-prompt — the prefix arg got swallowed at our wrapper layer.

Switched all four to `current-prefix-arg':
- `cj/--f4-dispatch' — `compile-only' and `run-only' actions.
- `cj/f4-compile-only' — the C-F4 fast path's compiled-project branch.
- `cj/f6-test-runner' — the "All tests" menu entry.

Use case: when projectile's cached cmd is wrong (typo, stale, or whatever), `C-u' on any of these forces projectile to re-prompt instead of replaying the bad cmd silently. The compile-and-run and clean-rebuild paths still pass nil to their chained projectile calls because those run inside an async `compilation-finish-functions' hook, where `current-prefix-arg' has already reverted to nil. Refining those would need to capture the prefix at entry and thread it through; left for later.

TDD: 4 new tests (one per call site) bind `current-prefix-arg' to t and verify projectile receives t. Each test failed against the literal-nil version and passes against `current-prefix-arg'.

1 files changed, 15 insertions, 0 deletions

diff --git a/tests/test-dev-fkeys--f6-test-runner.el b/tests/test-dev-fkeys--f6-test-runner.el
index 23129539..eb9cec5e 100644
--- a/tests/test-dev-fkeys--f6-test-runner.el
+++ b/tests/test-dev-fkeys--f6-test-runner.el
@@ -49,6 +49,21 @@
       (cj/f6-test-runner)
       (should (= calls 1)))))
 
+(ert-deftest test-dev-fkeys-f6-test-runner-all-tests-propagates-prefix-arg ()
+  "Normal: choosing 'All tests' forwards `current-prefix-arg' to
+projectile-test-project so `C-u F6 → All tests' forces a re-prompt."
+  (let ((seen-arg 'unset)
+        (current-prefix-arg t))
+    (cl-letf (((symbol-function 'completing-read)
+               (lambda (&rest _) "All tests"))
+              ((symbol-function 'projectile-test-project)
+               (lambda (arg) (setq seen-arg arg)))
+              ((symbol-function 'cj/--f4-project-root) (lambda () "/p/"))
+              ((symbol-function 'cj/--f6-current-file-tests-impl)
+               (lambda (_f _r) nil)))
+      (cj/f6-test-runner)
+      (should (eq seen-arg t)))))
+
 (ert-deftest test-dev-fkeys-f6-test-runner-current-file-routes-to-impl ()
   "Normal: choosing 'Current file's tests' invokes the orchestrator with
 the buffer file and projectile root.