v0.3.0 deferred: tab completion, multi-line, /help, activity indicator, context persistence, theming

- Tab completion: Tab key autocompletes / commands (Tab handler in on-key)
- Multi-line input: backslash + Enter inserts literal newline instead of sending
- /help command: displays full command listing with descriptions
- Activity indicator: :busy flag shows "...thinking" in status bar during LLM wait
- Context persistence: context-save/context-load persist *context-stack* to disk
  (~/.cache/passepartout/context.lisp). Auto-restores on skill load.
  Added push-context, pop-context, focus-*, unfocus, context-save/load exports.
- Theming: *tui-theme* plist with semantic color roles, /theme command
  View functions (view-chat, view-status, view-input) use theme-color
- TUI test suite: 19 tests, 53 checks (100% pass)
- Context test suite: 2 tests, 6 checks (100% pass)
- Total: 5 suites, 81 checks, 0 failures

lisp/system-context-manager.lisp

@@ -1,3 +1,5 @@
+(in-package :passepartout)
+
 (defvar *context-stack* nil
   "Stack of context plists. Each plist has :project, :base-path, :scope.
 Top of stack (car) is the current context.")
@@ -39,6 +41,7 @@ Returns the new context plist."
                         :base-path base-path
                         :scope scope)))
     (push context *context-stack*)
+    (context-save)
     (log-message "CONTEXT: Pushed ~a (depth ~d)" project (context-stack-depth))
     context))
 
@@ -47,6 +50,7 @@ Returns the new context plist."
 Returns the restored context or nil if stack becomes empty."
   (if *context-stack*
       (let ((popped (pop *context-stack*)))
+        (context-save)
         (log-message "CONTEXT: Popped ~a (depth ~d)"
                      (getf popped :project) (context-stack-depth))
         (current-context))
@@ -107,6 +111,46 @@ until stack is empty or :memex context is reached."
   "Pop the top context and return to the previous one."
   (pop-context))
 
+(defvar *context-persistence-file* nil
+  "Path to the context stack persistence file.")
+
+(defun context-persist-file ()
+  "Returns the full path to the context persistence file."
+  (or *context-persistence-file*
+      (setf *context-persistence-file*
+            (merge-pathnames ".cache/passepartout/context.lisp"
+                             (user-homedir-pathname)))))
+
+(defun context-save ()
+  "Writes *context-stack* to the persistence file."
+  (handler-case
+      (let ((path (context-persist-file)))
+        (ensure-directories-exist (make-pathname :directory (pathname-directory path)))
+        (with-open-file (s path :direction :output :if-exists :supersede
+                                 :if-does-not-exist :create)
+          (prin1 *context-stack* s))
+        (log-message "CONTEXT: Saved stack (depth ~d) to ~a"
+                     (length *context-stack*) path))
+    (error (c)
+      (log-message "CONTEXT: Failed to save: ~a" c))))
+
+(defun context-load ()
+  "Restores *context-stack* from the persistence file."
+  (handler-case
+      (let ((path (context-persist-file)))
+        (when (probe-file path)
+          (with-open-file (s path :direction :input)
+            (let ((*read-eval* nil)
+                  (data (read s nil nil)))
+              (when (listp data)
+                (setf *context-stack* data)
+                (log-message "CONTEXT: Restored stack (depth ~d) from ~a"
+                             (length *context-stack*) path))
+              t))))
+    (error (c)
+      (log-message "CONTEXT: Failed to load: ~a" c)
+      nil)))
+
 (defskill :passepartout-system-context-manager
   :priority 90
   :trigger (lambda (ctx) (declare (ignore ctx)) nil)
@@ -119,3 +163,40 @@ until stack is empty or :memex context is reached."
 
 (when (boundp '*scope-resolver*)
   (setf *scope-resolver* #'current-scope))
+
+;; Restore persisted context on load
+(context-load)
+
+(eval-when (:compile-toplevel :load-toplevel :execute)
+  (ql:quickload :fiveam :silent t))
+
+(defpackage :passepartout-context-tests
+  (:use :cl :passepartout)
+  (:export #:context-suite))
+
+(in-package :passepartout-context-tests)
+
+(fiveam:def-suite context-suite :description "Context manager verification")
+(fiveam:in-suite context-suite)
+
+(fiveam:test test-push-pop-context
+  "Contract 1-2: push-context and pop-context maintain stack order."
+  (let ((passepartout::*context-stack* nil))
+    (push-context :project "testapp" :base-path "/tmp" :scope :project)
+    (fiveam:is (= 1 (length passepartout::*context-stack*)))
+    (fiveam:is (string= "testapp" (getf (car passepartout::*context-stack*) :project)))
+    (pop-context)
+    (fiveam:is (null passepartout::*context-stack*))))
+
+(fiveam:test test-context-save-load
+  "Contract 3-4: context-save and context-load round-trip."
+  (let* ((tmpfile (merge-pathnames "test-context.lisp" (uiop:temporary-directory)))
+         (passepartout::*context-persistence-file* tmpfile)
+         (passepartout::*context-stack* (list '(:project "test" :base-path "/tmp" :scope :project))))
+    (context-save)
+    (fiveam:is (probe-file tmpfile))
+    (setf passepartout::*context-stack* nil)
+    (context-load)
+    (fiveam:is (= 1 (length passepartout::*context-stack*)))
+    (fiveam:is (string= "test" (getf (car passepartout::*context-stack*) :project)))
+    (delete-file tmpfile)))