v0.4.0: expanded theme — 27-color system + /theme presets

RED proofs (TUI REPL):
- (length *tui-theme*) → 14 (7 key-value pairs)
- (getf *tui-theme* :background) → NIL (no background key)
- (getf *tui-theme* :gate-passed) → NIL (no gate-trace colors)
- /theme dark → sent to daemon as user input (not handled)

GREEN proofs (TUI REPL):
- theme-switch :light → :LIGHT (preset loaded)
- theme-switch :dark → :DARK (restoration works)
- /theme solarized shows theme switched message
- Tab completes theme names (/theme so|lar → /theme solarized)

Changes:
- *tui-theme*: 7 keys → 27 keys (roles, content, status, gate trace,
  tools, display, differentiator, UI)
- *tui-theme-presets*: dark, light, gruvbox (ansi + RGB), solarized (RGB)
- theme-switch(name): loads preset, persists to disk
- theme-save/theme-load: ~/.cache/passepartout/theme.lisp persistence
- /theme command: bare = show current theme + available presets
- /theme <name>: switch to named preset with feedback
- Tab completion: theme names after '/theme ' prefix
- tui-main: calls theme-load on startup

Test: 112/0 across 14 suites.

org/gateway-tui-model.org

@@ -33,9 +33,91 @@ All state mutation flows through event handlers in the controller.
 (defvar *event-lock* (bt:make-lock "tui-event-lock"))
 
 (defvar *tui-theme*
-  '(:user :green :agent :white :system :yellow :input :cyan
-    :connected :green :disconnected :red :timestamp :yellow)
-  "Color theme plist. Keys are semantic roles, values are Croatoan colors.")
+  ;; Roles
+  '(:user :green :agent :white :system :yellow
+    ;; Content
+    :input :cyan :timestamp :yellow :help :cyan :error :red :warning :yellow
+    ;; Status
+    :connected :green :disconnected :red :busy :magenta :idle :white
+    ;; Gate trace
+    :gate-passed :green :gate-blocked :red :gate-approval :yellow
+    ;; Tools (future use)
+    :tool-running :magenta :tool-success :green :tool-failure :red :tool-output :white
+    ;; Display
+    :scroll-indicator :cyan :border :white :background :black
+    ;; Differentiator (v0.4.0)
+    :rule-count :cyan :focus-map :yellow
+    ;; UI
+    :dim :white :highlight :cyan :accent :green)
+  "Color theme plist. 27 semantic keys → Croatoan color values.
+See *tui-theme-presets* for named presets (dark, light, solarized, gruvbox).")
+
+(defvar *tui-theme-presets*
+  '(:dark  (:user :green :agent :white :system :yellow
+            :input :cyan :timestamp :yellow :help :cyan :error :red :warning :yellow
+            :connected :green :disconnected :red :busy :magenta :idle :white
+            :gate-passed :green :gate-blocked :red :gate-approval :yellow
+            :tool-running :magenta :tool-success :green :tool-failure :red :tool-output :white
+            :scroll-indicator :cyan :border :white :background :black
+            :rule-count :cyan :focus-map :yellow
+            :dim :white :highlight :cyan :accent :green)
+    :light (:user :blue :agent :black :system :red
+            :input :black :timestamp :yellow :help :blue :error :red :warning :yellow
+            :connected :green :disconnected :red :busy :magenta :idle :black
+            :gate-passed :green :gate-blocked :red :gate-approval :yellow
+            :tool-running :magenta :tool-success :green :tool-failure :red :tool-output :black
+            :scroll-indicator :blue :border :black :background :white
+            :rule-count :blue :focus-map :red
+            :dim :white :highlight :blue :accent :green)
+    :gruvbox (:user "#458588" :agent "#ebdbb2" :system "#fabd2f"
+              :input "#ebdbb2" :timestamp "#928374" :help "#83a598" :error "#fb4934" :warning "#fabd2f"
+              :connected "#b8bb26" :disconnected "#fb4934" :busy "#d3869b" :idle "#a89984"
+              :gate-passed "#b8bb26" :gate-blocked "#fb4934" :gate-approval "#fabd2f"
+              :tool-running "#d3869b" :tool-success "#b8bb26" :tool-failure "#fb4934" :tool-output "#ebdbb2"
+              :scroll-indicator "#83a598" :border "#a89984" :background "#282828"
+              :rule-count "#83a598" :focus-map "#fabd2f"
+              :dim "#928374" :highlight "#83a598" :accent "#b8bb26")
+    :solarized (:user "#268bd2" :agent "#839496" :system "#b58900"
+                :input "#839496" :timestamp "#93a1a1" :help "#2aa198" :error "#dc322f" :warning "#b58900"
+                :connected "#859900" :disconnected "#dc322f" :busy "#d33682" :idle "#657b83"
+                :gate-passed "#859900" :gate-blocked "#dc322f" :gate-approval "#b58900"
+                :tool-running "#d33682" :tool-success "#859900" :tool-failure "#dc322f" :tool-output "#839496"
+                :scroll-indicator "#2aa198" :border "#657b83" :background "#002b36"
+                :rule-count "#2aa198" :focus-map "#b58900"
+                :dim "#586e75" :highlight "#2aa198" :accent "#859900"))
+  "Named theme presets. /theme <name> loads one into *tui-theme*.")
+
+(defvar *tui-theme-current-name* :dark
+  "Name of the currently active theme preset.")
+
+(defun theme-save ()
+  "Persist current theme to disk."
+  (let ((path (merge-pathnames ".cache/passepartout/theme.lisp"
+                               (user-homedir-pathname))))
+    (uiop:ensure-all-directories-exist (list path))
+    (with-open-file (out path :direction :output :if-exists :supersede :if-does-not-exist :create)
+      (format out ";; Passepartout TUI theme — auto-generated~%")
+      (format out "(setf passepartout.gateway-tui::*tui-theme* '~s)~%" *tui-theme*)
+      (format out "(setf passepartout.gateway-tui::*tui-theme-current-name* ~s)~%" *tui-theme-current-name*))
+    t))
+
+(defun theme-load ()
+  "Load persisted theme from disk. Called at startup."
+  (let ((path (merge-pathnames ".cache/passepartout/theme.lisp"
+                               (user-homedir-pathname))))
+    (when (uiop:file-exists-p path)
+      (ignore-errors (load path)))))
+
+(defun theme-switch (name)
+  "Switch to a named theme preset. Returns the preset name or nil if not found."
+  (let* ((key (intern (string-upcase (string name)) :keyword))
+         (preset (getf *tui-theme-presets* key)))
+    (when preset
+      (setf *tui-theme* (copy-list preset)
+            *tui-theme-current-name* key)
+      (theme-save)
+      (setf (st :dirty) (list t t t))
+      key)))
 
 (defun theme-color (role)
   "Returns the Croatoan color for a semantic role."