feat: refine coding agent workspace

ARCHITECTURE.md

@@ -7,6 +7,7 @@ responsibility rather than by framework or build order.
 ```text
 Application/          App lifecycle and display selection
 Companion/            Idle/terminal presentation state and transparent panel
+Agent/                Coding-agent request construction and delivery state
 Terminal/
   Core/               ANSI parsing, buffer, paging, input encoding, value types
   PTY/                Pseudoterminal process and non-blocking I/O boundary
@@ -19,14 +20,19 @@ Assets/               Processed application and companion artwork
 Dependency direction is intentionally one-way:
 
 ```text
-Application + Companion -> Terminal Rendering -> Terminal Workspace/Session -> PTY + Core
+Application + Companion -> Agent + Terminal Rendering -> Terminal Workspace/Session -> PTY + Core
 ```
 
-`TerminalWorkspaceModel` is the only owner of tab/split topology. Every leaf
-maps to exactly one `TerminalSessionModel` and one `TerminalSessionID`-derived
-persistence file; views route focus and raw input to that leaf only. It never
+`MikuPanelCoordinator` owns one `TerminalSessionModel` for the one visible
+embedded PTY. Views route focus and raw input to that session only; it never
 creates another `NSWindow`.
 
+`AgentWorkspaceModel` is the UI-side owner of a coding-agent request. It
+constructs only supported provider/approval commands, hands them to the active
+`TerminalSessionModel`, and records the request in conversation history only
+after the PTY reports delivery for the matching request token. It does not own
+or create a second PTY, panel, or window.
+
 `Terminal/Core` contains deterministic terminal behavior and must not import
 SwiftUI, AppKit, Metal, or process-launch concerns. UI and process boundaries
 belong to their named directories; this keeps parser and buffer changes

CONTRIBUTING.md

@@ -1,6 +1,8 @@
 # Contributing to MikuCode
 
-Thanks for helping improve MikuCode. Contributions should make the macOS single-session terminal and companion UI clearer, more reliable, or more accessible while keeping its focused scope.
+Thanks for helping improve MikuCode. Contributions should make the macOS
+coding-agent workspace, local embedded terminal, or companion UI clearer,
+more reliable, or more accessible while keeping its focused one-panel scope.
 
 This private repository requires a GitHub-authorized account for cloning and contributing.
 

DESIGN.md

@@ -14,8 +14,8 @@ the Dock. Development `swift run` output is not part of the product UI.
 | --- | --- | --- |
 | `idle` | Transparent panel; a centered front-facing chibi Miku stays still, changes to attentive eye contact on hover, and reveals a terminal bubble | Stopped |
 | `opening` | Same panel transitions to the active composition | Stopped |
-| `terminal` | Screen-sized, borderless, normal-level panel with a large speech-bubble local-terminal workspace, compact MikuCode header, and Miku right rail | Each visible leaf is running and the focused pane is directly focused |
-| `closing` | Active composition leaves the same panel | PTYs stopped, drained, and persisted |
+| `terminal` | Screen-sized, borderless, normal-level panel with a large dark sky-blue speech-bubble coding-agent workspace, compact MikuCode header, and Miku right rail | The coordinator-owned local PTY runs whether its embedded view is shown or hidden |
+| `closing` | Active composition leaves the same panel | The local PTY stops, drains, and persists |
 
 Repeated or out-of-order events are no-ops. Command-W and panel-close requests
 use the close transition and return to `idle`.
@@ -33,23 +33,28 @@ use the close transition and return to `idle`.
   reveals a small speech-bubble terminal affordance. The companion never walks,
   slides, or bobs in idle; only the intentional gaze state changes.
   Clicking either Miku herself or that bubble begins the terminal transition.
-- In terminal state, the bubble header contains `miku-code`, a horizontally
-  scrollable selected-tab strip, the actual focused-PTY state, and one close
-  control. `Command-T` creates a tab, `Command-D` splits the focused pane to
-  the right, and `Shift-Command-D` splits it below; these actions retain the
-  one-panel, one-bubble composition. Hovering expanded Miku reveals a close
+- In terminal state, the bubble opens as a coding-agent workspace: a compact
+  MikuCode logo mark gives way to prompt history, a provider/approval composer, and
+  a terminal toggle. Codex and Claude support `Plan`, `Accept`, and `Auto`;
+  the workspace only records a request after its token-matched PTY delivery.
+  The terminal toggle reveals that same local PTY inside the bubble—never a
+  second window. Hovering expanded Miku reveals a close
   marker. Clicking either close
   target stops the terminal and returns the same running app to its small idle
   companion at the floating layer; it only returns behind other apps after the
   app itself loses focus, and never quits MikuCode.
-- The terminal header is an agent-workspace cue, not a toolbar: it contains the
-  app name, tab navigation, the actual focused-PTY state, and one close
-  control. There are no traffic
-  lights, provider selectors, paging/search controls, or permanent Clear,
-  Interrupt, or Send buttons. Command-F opens the only transient text field: a
-  compact in-bubble terminal finder. Command-G and Shift-Command-G navigate
-  its case-insensitive matches across output pages; Escape restores terminal
-  focus and removes the finder.
+- The workspace header is an agent-workspace cue, not a toolbar: it contains
+  the logo mark, local-shell status, an embedded-terminal toggle, and one close
+  control. The composer is a measured bottom dock: provider and approval chips
+  remain distinct from a full-width prompt field and labelled send action at all
+  supported bubble sizes. Codex uses a cool gray signal, Claude orange, and
+  Plan/Accept/Auto each retain distinct semantic colors. Command-F opens the only
+  transient terminal text field: a compact in-bubble finder. Command-G and
+  Shift-Command-G navigate its case-insensitive matches across output pages;
+  Escape restores terminal focus and removes the finder.
+- The speech-bubble tail owns a reserved header inset; terminal and close controls
+  never sit beneath it, and the focused-Miku close target begins after a fixed gap
+  beyond the workspace frame. No interactive target is allowed to overlap another.
 - The speech bubble resizes directly from its edges and corners. Its frame stays
   inside a 24-point display inset and preserves a minimum right-side Miku rail;
   native directional cursors expose the otherwise unobtrusive resize targets.
@@ -66,21 +71,20 @@ event monitor is used.
 
 PTY output is read without blocking, input is bounded and drained through a
 write source, resize is sent through `TIOCSWINSZ`, and shutdown sends `SIGHUP`
-with a bounded `SIGKILL` fallback. Each workspace leaf owns its own PTY and
-bounded snapshot; the tab/split/focus layout and per-session snapshots persist
-on close and restore on the next launch.
+with a bounded `SIGKILL` fallback. The coordinator-owned PTY and its bounded
+snapshot persist on close and restore on the next launch.
 
 ## Visual tokens
 
 The visual system uses a 4-point spacing base. Idle is transparent; active
-surfaces use a graphite two-stop bubble, a translucent rim, a restrained teal
-shadow, and white terminal text. The header uses compact rounded app type with
-monospaced `agent terminal` and PTY state labels, making the surface read as a
+surfaces use flat dark sky-blue tones, a translucent cyan rim with a slow opacity
+pulse, a restrained teal shadow, and white terminal text. The header uses modern
+SF app type with small monospaced agent labels, making the surface read as a
 coding-agent workspace rather than a generic terminal emulator. The app icon is a separate
 terminal-and-Miku asset; the desktop companion contains only the 2D Miku
 character. Idle artwork stays centered and still above a subtle teal ground
 shadow. Its only idle motion is an intentional crossfade to an attentive gaze
 on hover; opening, active terminal, and closing states use the focus frame as
-the deliberate zoom transition. ANSI colors
-are confined to terminal output. Reduce Motion removes companion float and
-state transitions while preserving state changes.
+the deliberate zoom transition. ANSI colors are confined to terminal output.
+Reduce Motion removes companion float and state transitions while preserving
+state changes.

README.md

@@ -1,25 +1,28 @@
 # MikuCode
 
-MikuCode is a macOS menu-bar-style companion that becomes a focused local PTY
-terminal in place. One transparent, persistent `NSPanel` owns both states:
-the idle panel shows Miku on the display under the pointer, and the active panel
-fills the display with a speech-bubble terminal and Miku on the right.
+MikuCode is a macOS coding-agent desktop with an integrated local PTY. One
+transparent, persistent `NSPanel` owns both states: the idle panel shows Miku
+on the display under the pointer, and the active panel fills the display with a
+dark sky-blue speech-bubble workspace and Miku on the right.
 
 ## Behavior
 
 - The PTY output view is selectable and receives keyboard input directly.
 - Miku stays still and front-facing in her idle area. Hovering crossfades to an
   attentive gaze and reveals a small terminal speech bubble; selecting either
   Miku or that bubble opens the full terminal in the same panel.
-- The expanded terminal uses the default MikuCode theme with a compact
-  `miku-code` header, a horizontally scrollable tab strip, and one close
-  button. `Command-T` opens a new local shell tab; `Command-D` splits the
-  focused terminal to the right; `Shift-Command-D` splits it below. Each leaf
-  owns an independent PTY, transcript, current directory, and persisted
-  session snapshot. Selecting the expanded Miku or the
-  close button returns the same running app to its small idle Miku without
+- The expanded workspace uses the default MikuCode theme with a compact
+  `miku-code` header, one embedded-terminal toggle, and one close button. The
+  coordinator owns one local PTY, transcript, current directory, and persisted
+  session snapshot. Selecting the expanded Miku or the close button returns
+  the same running app to its small idle Miku without
   sending it behind other windows; it returns to the desktop layer only after
   the app loses focus, and never quits MikuCode.
+- The agent workspace starts with a centered MikuCode mark and a focused
+  prompt composer. Choose Codex or Claude plus `Plan`, `Accept`, or `Auto`;
+  the request is written to the integrated PTY only after the local terminal
+  can accept it. The terminal button expands or hides that same embedded PTY
+  below the conversation—no second window is created.
 - Printable keys, control sequences, paste, resize, paging, find, clear, and
   interrupt use terminal keyboard actions. Command-F opens a compact transient
   finder inside the terminal bubble; Command-G and Shift-Command-G move between
@@ -44,9 +47,9 @@ in [ARCHITECTURE.md](ARCHITECTURE.md).
 
 - `MikuPanelCoordinator` retains the single panel and applies the presentation
   state machine.
-- `TerminalWorkspaceModel` owns tabs, focused-pane splits, per-session
-  storage, and workspace restoration while retaining one outer speech bubble.
-- `TerminalPanel` embeds an individual terminal pane.
+- `AgentWorkspaceModel` owns provider/approval selection and only records an
+  agent prompt after its PTY write is confirmed.
+- `TerminalPanel` embeds the coordinator-owned terminal pane.
 - `TerminalSessionModel` owns one PTY lifecycle, buffering, persistence, and
   terminal updates.
 - `PTYProcess` uses `forkpty`, a bounded non-blocking output/input path, and
@@ -73,9 +76,10 @@ Requirements: macOS 14 or later, Swift 6 or later, and a local POSIX shell.
 
 ## Scope
 
-MikuCode provides local shell tabs and focused-pane splits inside one panel.
-Remote connections, profiles, SSH, editor features, tab closing/reordering,
-and complete terminal compatibility are out of scope. The protocol
+MikuCode provides one local shell and coding-agent prompts inside one panel.
+Remote connections, profiles, SSH, editor features, terminal tabs/splits,
+provider-specific session restoration, and complete terminal compatibility are
+out of scope. The protocol
 intentionally covers a focused subset of UTF-8, ANSI SGR, cursor movement,
 erasure, and bracketed paste behavior.