feat: TUI settings panel on key 6 with per-section preference editors backed by the same GUI settings backends (issue #29)

specs/tui.allium

@@ -4,7 +4,7 @@
 -- Distilled from: lib/bds/tui.ex, lib/bds/ui/sidebar.ex, lib/bds/ui/post_editor/*.ex
 
 entity TuiState {
-    view: posts | media | templates | scripts | tags
+    view: posts | media | templates | scripts | tags | settings | git
     focus: sidebar | editor
     selected_index: Integer
     editing_post: Boolean
@@ -116,6 +116,24 @@ rule CommandPrompt {
     ensures: CommandListShownOrExecuted()
 }
 
+rule SettingsPanel {
+    when: TuiKeyPressed(code: "6")
+    -- "6" opens the settings panel (issue #29), matching the GUI panel
+    -- numbering: the sidebar lists the same preference sections as the
+    -- GUI settings editor (Project, Editor, Content, AI, Technology,
+    -- Publishing, Data, MCP, Style — from BDS.UI.Sidebar's settings
+    -- view). Enter on a section opens a section-specific editor in the
+    -- main area: a generic typed-field form from BDS.UI.SettingsForm.
+    -- Enter edits a text field in a status-line prompt, toggles a
+    -- boolean, or cycles an enum through its options; read-only info
+    -- rows are skipped by the selection. ctrl+s saves the section
+    -- through the same backends as the GUI editor (BDS.Metadata,
+    -- BDS.Settings, BDS.AI, BDS.MCP.AgentConfig) and reloads the form;
+    -- esc cancels the prompt, then closes the form. Category removal
+    -- and AI model discovery remain GUI-only.
+    ensures: SettingsFormShownEditedOrSaved()
+}
+
 rule GitPanel {
     when: TuiKeyPressed(code: "7")
     -- "7" opens the git panel (issue #30) for content sync: the sidebar