feat(chat): queue in-flight sends and batch queued drafts

Keep user intent while a response is running by showing queued messages and dispatching them as one payload when possible. Add Send now, retry-safe queue draining, and docs/tests to lock behavior.

Author: insign

BEHAVIOR.md

@@ -0,0 +1,373 @@
+# Behavior Specification
+
+> How CodeWalk behaves from the user's perspective.
+> Only documents **current, implemented** behavior. Planned features live in ROADMAP.md.
+
+---
+
+## Onboarding
+
+### First launch shows setup wizard
+
+- **Given** the app is opened for the first time (no servers configured)
+- **When** the app starts
+- **Then** a setup wizard is displayed requiring the user to configure at least one OpenCode server
+
+### No server = no functionality
+
+- **Given** no server is configured
+- **When** the user tries to access any feature
+- **Then** the app blocks access — configuring a server is a prerequisite for all functionality
+
+---
+
+## Servers
+
+### Multiple server profiles
+
+- **Given** the user is in server settings
+- **When** the user adds a new server profile (local, remote, work, etc.)
+- **Then** the profile is saved and the user can switch between profiles at any time
+
+### Automatic health checks
+
+- **Given** server profiles are configured
+- **When** the app is active
+- **Then** the app periodically checks each server's health and shows a visual online/offline indicator
+
+### Server goes offline during use
+
+- **Given** the active server goes offline while the user is chatting
+- **When** the connection is lost
+- **Then** the composer input is blocked and the reason is displayed to the user
+- **Then** the user cannot send messages until the connection is restored
+
+> **Current state**: the offline error is too aggressive (full-screen error with "Retry"). The desired behavior is a subtle composer block with a clear reason message.
+
+---
+
+## Sessions
+
+### Session lifecycle
+
+- **Given** a connected server
+- **When** the user interacts with sessions
+- **Then** the user can **create**, **rename**, **archive**, **fork**, and **delete** sessions
+
+### Fork creates an independent copy
+
+- **Given** an existing session with conversation history
+- **When** the user forks the session
+- **Then** a new independent session is created as a copy from that point — changes to either session do not affect the other
+
+### Sessions are scoped to a project
+
+- **Given** the user has multiple projects/workspaces
+- **When** the user switches to a different project
+- **Then** the visible session list changes to show only sessions belonging to that project
+
+### Auto-generated session titles
+
+- **Given** a new session with no custom title
+- **When** the conversation progresses
+- **Then** the app automatically generates a title based on the conversation content
+
+---
+
+## Chat
+
+### Messages are streamed in real time
+
+- **Given** a connected server and an active session
+- **When** the user sends a message
+- **Then** the message is sent to the OpenCode server and the assistant's response streams back via SSE, rendering in real time as text arrives
+
+### User can cancel a response
+
+- **Given** the assistant is actively streaming a response
+- **When** the user taps the cancel/stop button
+- **Then** the response generation stops and the partial response remains visible
+
+### Sending while processing enqueues messages
+
+- **Given** the assistant is actively streaming a response
+- **When** the user sends one or more new messages
+- **Then** each new message is shown in the timeline immediately as queued (with `Queued` state)
+- **Then** the app does not interrupt the running response automatically
+
+### Queued messages are batched into one send
+
+- **Given** there are multiple queued messages for the same session
+- **When** the queue is dispatched (either on first idle opportunity or via `Send now`)
+- **Then** all queued message texts are merged and sent as a single payload
+- **Then** each original queued message becomes one line in that payload (simple `\n` line breaks between messages)
+
+### Send now forces immediate queued dispatch
+
+- **Given** there are queued messages while the assistant is still processing
+- **When** the user taps `Send now`
+- **Then** the app performs the same stop behavior as `Stop` for the active response
+- **Then** as soon as the session becomes ready, the app sends the full queued batch as one payload
+
+### Failed send returns message to composer
+
+- **Given** the user sends a message
+- **When** the send fails (network error, server error, etc.)
+- **Then** the message text is returned to the composer input — the user's text is never lost
+
+### Tool call work groups collapse after completion
+
+- **Given** the assistant executes tool calls during a response (file reads, commands, etc.)
+- **When** the assistant finishes the complete response
+- **Then** the intermediate tool call groups collapse to keep the chat clean
+- **Then** collapse never happens while the assistant is still streaming
+
+### UI remains fluid during streaming
+
+- **Given** the assistant is streaming a long response
+- **When** text, code blocks, or tool calls render incrementally
+- **Then** the UI remains smooth without stuttering, freezing, or perceptible lag
+
+---
+
+## Composer
+
+### Message history navigation
+
+- **Given** the user has sent previous messages in the session
+- **When** the user presses the up/down arrow keys in the composer
+- **Then** the composer cycles through previously sent messages
+
+### File mentions with @
+
+- **Given** the user is typing in the composer
+- **When** the user types `@`
+- **Then** a file/context mention picker appears, allowing the user to reference project files in the message
+
+### Slash commands with /
+
+- **Given** the user is typing in the composer
+- **When** the user types `/`
+- **Then** a command picker appears with available slash commands
+
+---
+
+## Attachments
+
+### Image and PDF attachments
+
+- **Given** the user is composing a message
+- **When** the user attaches an image or PDF
+- **Then** the file is attached to the message and sent along with the text
+
+### Model capability gating
+
+- **Given** the selected model does not support vision
+- **When** the user tries to attach an image
+- **Then** the attachment option is disabled or shows clear feedback that the model cannot process images
+
+---
+
+## Voice Input
+
+### Speech-to-text in the composer
+
+- **Given** the user activates voice input
+- **When** the user speaks
+- **Then** the speech is converted to text and inserted into the composer input
+
+### Cross-platform support
+
+- **Given** any supported platform (Android, Linux, macOS, Windows, Web)
+- **When** the user activates voice input
+- **Then** the STT feature works on all platforms where the device has a microphone
+
+---
+
+## Interactive Prompts
+
+### Permission requests
+
+- **Given** the server needs user approval to perform an action (e.g., execute a command, write a file)
+- **When** the server sends a permission request
+- **Then** an interactive card appears in the chat with approve/deny options
+- **Then** the server waits for the user's response before proceeding
+
+### Question prompts
+
+- **Given** the server needs the user to choose between options
+- **When** the server sends a question prompt
+- **Then** an interactive card appears with the question and selectable options
+- **Then** the server waits for the user's response before proceeding
+
+---
+
+## File Explorer
+
+### Read-only project tree
+
+- **Given** the user opens the file explorer panel
+- **When** the project tree loads
+- **Then** the user sees the file/folder structure of the current project in read-only mode (no create, edit, or delete)
+
+### File preview
+
+- **Given** the file explorer is open
+- **When** the user taps a file
+- **Then** a preview/visualization of the file content is shown
+
+---
+
+## Task List
+
+### Agent-controlled task list
+
+- **Given** the AI agent is executing a multi-step task
+- **When** the agent reports its task progress
+- **Then** a task list is displayed in the session showing the agent's current and completed steps
+- **Then** the task list is read-only for the user — it is controlled entirely by the server/agent
+
+---
+
+## Layout
+
+### Mobile: chat-first with drawer
+
+- **Given** the app is running on a mobile device (compact screen)
+- **When** the user navigates the app
+- **Then** the chat occupies the full screen, with the session list accessible via a lateral drawer
+
+### Desktop: split view
+
+- **Given** the app is running on a desktop (expanded screen)
+- **When** the user navigates the app
+- **Then** the session list is always visible alongside the chat in a split-view layout
+
+### Keyboard shortcuts
+
+- **Given** a physical keyboard is connected (desktop or mobile with external keyboard)
+- **When** the user presses a keyboard shortcut
+- **Then** the corresponding action is executed (shortcuts work on desktop and on mobile with an external keyboard)
+
+### Mobile keyboard collapses auxiliary panels
+
+- **Given** an auxiliary panel is open (task list, drawer, etc.) on mobile
+- **When** the on-screen keyboard appears
+- **Then** auxiliary panels auto-collapse to maximize available space for the chat and composer
+
+---
+
+## Settings
+
+### Theme selection
+
+- **Given** the user is in settings
+- **When** the user selects a theme
+- **Then** the app supports light, dark, and AMOLED themes, plus Material You dynamic color from the system wallpaper
+
+### Local persistence
+
+- **Given** the user changes any setting
+- **When** the setting is saved
+- **Then** it persists locally (survives app restart) via SharedPreferences / SecureStorage
+
+---
+
+## Notifications
+
+### Background notifications
+
+- **Given** the app is in the background
+- **When** the assistant finishes a response → push notification
+- **When** a permission request arrives → push notification
+- **When** a question prompt arrives → push notification
+
+### Server offline does NOT notify
+
+- **Given** the active server goes offline
+- **When** the app detects the disconnection
+- **Then** no push notification is sent — server availability is not the app's responsibility. The user sees the status when they open the app.
+
+### Android persistent notification
+
+- **Given** the app is running on Android
+- **When** the app is active or in background
+- **Then** a persistent notification acts as a tray icon, enabling reliable notification delivery
+
+---
+
+## Background and Lifecycle
+
+### Android foreground service
+
+- **Given** the app is running on Android during a long operation
+- **When** the app goes to background
+- **Then** a foreground service keeps the app alive so the operation is not killed by the system
+
+### Battery optimization prompt
+
+- **Given** the app is running on Android
+- **When** battery optimization may interfere with background operation
+- **Then** the app prompts the user to disable battery optimization
+
+### Automatic reconnection on resume
+
+- **Given** the app was in background
+- **When** the user returns to the app
+- **Then** the app automatically reconnects to the server and resynchronizes state (missed messages, updated sessions, etc.)
+
+### No duplicate refresh on resume
+
+- **Given** the app resumes from background
+- **When** both lifecycle and reconnect triggers fire
+- **Then** only one refresh cycle executes — no duplicate network calls
+
+---
+
+## Anti-behaviors
+
+> Things that must **never** happen, regardless of circumstances.
+
+### Never lose user messages
+
+The app must never silently discard a user's message. If sending fails, the message text returns to the composer input.
+
+### Never freeze the UI
+
+All operations (streaming, sync, network) are asynchronous. The UI must never become unresponsive, even during heavy operations.
+
+### Never expose tokens or credentials
+
+Server tokens, API keys, and credentials must never appear in logs, error screens, exports, or any user-visible surface.
+
+### Never auto-approve permissions
+
+Permission requests from the server always require explicit user action (approve or deny). The app must never approve automatically.
+
+### Never show false aborts
+
+When a connection drops and reconnects (especially on mobile background/resume), the app must not display false "message aborted" errors from stale SSE events.
+
+### Never corrupt state on rapid actions
+
+If the user taps rapidly (double-tap on sessions, fast project switching), the app processes one transition at a time. Concurrent transitions must never corrupt state or cause navigation errors.
+
+### Never cancel responses on session switch
+
+If the assistant is streaming a response and the user switches to a different session, the in-flight response must be preserved — not cancelled. The user can return to the original session and see the completed response.
+
+### Never collapse work groups during streaming
+
+Tool call work groups must only collapse after the assistant has fully completed its response. Premature collapse causes visual flicker and hides active work.
+
+### Never show stale data after resume
+
+When the app returns from background, it must refresh the current session to show the latest state. However, refresh must not re-inject stale abort data that was already handled.
+
+### Never break layout with keyboard
+
+On mobile, the on-screen keyboard must never cause overflow, clipping, or layout breakage. Fixed minimum heights must account for the keyboard-reduced viewport.
+
+### Errors: only show blocking ones
+
+The user should see error feedback only when the error prevents them from continuing (send failed, server unreachable). Non-blocking warnings from the server (partial timeouts, transient issues) should be silent.

CODEBASE.md

@@ -245,6 +245,12 @@ tool/ci/check_coverage.sh              # Coverage threshold gate (default: 35%)
 - Android build targets Java 17 (`sourceCompatibility`, `targetCompatibility`, `jvmTarget`).
 - featM icon migration completed in `lib/presentation/**` and `test/widget/**`: Material icons moved from `Icons.*` to `Symbols.*` (`material_symbols_icons`).
 
+### Queued Send Flow
+
+- **Provider queue state + drain/send-now**: `chat_provider.dart` tracks per-session queued envelopes/local queued IDs and drains them as a merged batch; `sendQueuedNow()` can stop active response and force immediate drain.
+- **Composer queued status + action**: `chat_page_composer_status.dart` prioritizes queued-count status, and `chat_page_composer_widgets.dart` renders queued UI with a `Send now` action.
+- **Queued message badge**: `chat_message_widget.dart` + `chat_message_content.dart` expose/render `isQueuedUserMessage` with a `Queued` badge in user message bubbles.
+
 ### Android Background Monitoring
 
 - **Native foreground service** (`android/app/src/main/kotlin/com/verseles/codewalk/CodeWalkForegroundService.kt`):

ROADMAP.featQ.md

@@ -59,6 +59,7 @@
   - [ ] Plan the merge between the project selector and the conversations sidebar, grouping conversations by open projects to speed up navigation.
   - [ ] Tasks widget gets a footer progress bar based on total completed items.
   - [x] Plan support for sending a new message while the assistant is still working (OpenCode CLI/Web parity), following existing OpenCode interaction patterns. - Planning doc: `ROADMAP.featQ.concurrent-send-plan.md`
+  - [x] Deliver queued-send behavior while processing: queue new messages during active run; `Send now` aborts current run and sends queued content; multiple queued drafts merge into one payload with single `\n` separators; show queued status/indicators in composer/chat UI. - Related commits: dfd64eb f8df06a c8884b2
   - [ ] Allow pinning sessions in the Conversations sidebar.
 
 ## Goal