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'.

4 files changed, 51 insertions, 4 deletions

diff --git a/modules/dev-fkeys.el b/modules/dev-fkeys.el
index 9c695674..a6f41adf 100644
--- a/modules/dev-fkeys.el
+++ b/modules/dev-fkeys.el
@@ -113,8 +113,8 @@ Installs a one-shot `compilation-finish-functions' hook to chain the run."
   "Route ACTION (a symbol from `cj/--f4-candidates') to its handler.
 Signals `user-error' on an unrecognized symbol or nil."
   (pcase action
-    ('compile-only    (projectile-compile-project nil))
-    ('run-only        (projectile-run-project nil))
+    ('compile-only    (projectile-compile-project current-prefix-arg))
+    ('run-only        (projectile-run-project current-prefix-arg))
     ('compile-and-run (cj/--f4-compile-and-run-impl))
     ('clean-rebuild   (cj/--f4-clean-rebuild-impl (cj/--f4-project-root)))
     ('compile-plain   (call-interactively #'compile))
@@ -329,7 +329,7 @@ get a no-op message. Outside any project, falls back to interactive
   (let* ((root (cj/--f4-project-root))
          (project-type (cj/--detect-project-type root)))
     (pcase project-type
-      ('compiled    (projectile-compile-project nil))
+      ('compiled    (projectile-compile-project current-prefix-arg))
       ('interpreted (message "C-F4: not a compiled language"))
       (_            (call-interactively #'compile)))))
 
@@ -342,7 +342,7 @@ Prompts via `completing-read' between \"All tests\" (delegates to
   (let* ((candidates '("All tests" "Current file's tests"))
          (label (completing-read "F6: " candidates nil t nil nil (car candidates))))
     (pcase label
-      ("All tests" (projectile-test-project nil))
+      ("All tests" (projectile-test-project current-prefix-arg))
       ("Current file's tests"
        (cj/--f6-current-file-tests-impl
         (buffer-file-name) (cj/--f4-project-root))))))
diff --git a/tests/test-dev-fkeys--f4-compile-only.el b/tests/test-dev-fkeys--f4-compile-only.el
index b0eec367..815aa097 100644
--- a/tests/test-dev-fkeys--f4-compile-only.el
+++ b/tests/test-dev-fkeys--f4-compile-only.el
@@ -36,6 +36,18 @@
         (cj/f4-compile-only)
         (should (= calls 1))))))
 
+(ert-deftest test-dev-fkeys-f4-compile-only-propagates-prefix-arg ()
+  "Normal: on a compiled project, `current-prefix-arg' is forwarded to
+projectile-compile-project so `C-u C-F4' forces a re-prompt."
+  (test-dev-fkeys-co--with-project '("go.mod")
+    (let ((seen-arg 'unset)
+          (current-prefix-arg t))
+      (cl-letf (((symbol-function 'cj/--f4-project-root) (lambda () root))
+                ((symbol-function 'projectile-compile-project)
+                 (lambda (arg) (setq seen-arg arg))))
+        (cj/f4-compile-only)
+        (should (eq seen-arg t))))))
+
 (ert-deftest test-dev-fkeys-f4-compile-only-interpreted-project-skips-compile ()
   "Normal: on an interpreted project, projectile-compile-project does not run."
   (test-dev-fkeys-co--with-project '("pyproject.toml")
diff --git a/tests/test-dev-fkeys--f4-dispatch.el b/tests/test-dev-fkeys--f4-dispatch.el
index 774daebf..0bf667a7 100644
--- a/tests/test-dev-fkeys--f4-dispatch.el
+++ b/tests/test-dev-fkeys--f4-dispatch.el
@@ -23,6 +23,26 @@
       (cj/--f4-dispatch 'compile-only)
       (should (= calls 1)))))
 
+(ert-deftest test-dev-fkeys-dispatch-compile-only-propagates-prefix-arg ()
+  "Normal: 'compile-only forwards `current-prefix-arg' to
+projectile-compile-project so `C-u F4 → Compile' forces a re-prompt."
+  (let ((seen-arg 'unset)
+        (current-prefix-arg t))
+    (cl-letf (((symbol-function 'projectile-compile-project)
+               (lambda (arg) (setq seen-arg arg))))
+      (cj/--f4-dispatch 'compile-only)
+      (should (eq seen-arg t)))))
+
+(ert-deftest test-dev-fkeys-dispatch-run-only-propagates-prefix-arg ()
+  "Normal: 'run-only forwards `current-prefix-arg' to
+projectile-run-project."
+  (let ((seen-arg 'unset)
+        (current-prefix-arg t))
+    (cl-letf (((symbol-function 'projectile-run-project)
+               (lambda (arg) (setq seen-arg arg))))
+      (cj/--f4-dispatch 'run-only)
+      (should (eq seen-arg t)))))
+
 (ert-deftest test-dev-fkeys-dispatch-run-only-calls-projectile-run ()
   "Normal: 'run-only routes to projectile-run-project."
   (let ((calls 0))
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.