feat(agent): add chat maximize/minimize feature for agent panel

- Introduced a new icon button in the agent chat header to toggle the chat section between maximized and minimized states, enhancing vertical space for chat logs while keeping Tasks, Context, and compose visible.
- Implemented a compact voice hero style (`agent-hero--compact`) for the minimized state.
- Added localization keys for the maximize and restore actions across all supported languages.
- Updated styles to support the new compact layout and button interactions.

Author: iptoux

.agents/plans/PLANS.md

@@ -15,3 +15,4 @@ Persistent plans for multi-step work on **blxcode**. Individual plans live as Ma
 | planned | [kanban-board-view.md](kanban-board-view.md) | Kanban-View im Plans-Panel fuer alle Plan-Tasks eines Workspaces: Status-Spalten, Drag-and-Drop fuer Karten und Spalten, Spalten ein-/ausblenden und Markdown-Writeback |
 | done | [coordinated-subagents.md](coordinated-subagents.md) | Coordinated Subagents fuer BLXCode Agent mit Rollen, i18n Live-Subcards, Provider-Reuse, Environment Detection, Shell/Git/Web Toolsets und scoped Toolgruppen |
 | done | [better-harness.md](better-harness.md) | BetterHarness: Shrink system prompt by extracting tool docs into 6 embedded Core Skills; Skills tab gets Core/User sub-tabs |
+| done | [agent-chat-maximize.md](agent-chat-maximize.md) | Agent-Tab: Chat-Maximize-Toggle vor Reset; Voice-Hero kompakt (`agent-hero--compact`), mehr Platz fuer Chat-Verlauf |

.agents/plans/agent-chat-maximize.md

@@ -0,0 +1,27 @@
+# Agent Chat Section Maximize
+
+**Status:** done (implemented on `feat/agent-chat-maximize`)
+
+## Summary
+
+Icon-Toggle im Agent-Tab-Chat-Header (vor Reset): maximiert die Chat-Sektion, indem der Voice-Hero (`agent-hero`) in eine kompakte Leiste wechselt. Tasks, Context und Compose bleiben sichtbar. Nur innerhalb des Agent-Right-Panel-Tabs.
+
+## Decisions
+
+- Voice minimieren via `agent-hero--compact`, kein Ausblenden von Tasks/Context.
+- Lokales `chat_maximized` RwSignal, nicht in `WorkspaceEntry`.
+- Feature-Branch: `feat/agent-chat-maximize` von `main`.
+
+## Tests
+
+- Agent-Tab: Toggle links vom Reset; Hero kompakt/voll; andere Tabs unberührt.
+- `cargo check -p blxcode-ui --target wasm32-unknown-unknown`
+
+## Tasks
+
+- [x] `git-branch` - Branch von main
+- [x] `plan-file` - Plan + PLANS.md Index
+- [x] `i18n-keys` - AgChatMaximize / AgChatRestore
+- [x] `ui-toggle` - Button + Signal + Hero-Modifier
+- [x] `css-hero-compact` - Compact hero + icon button styles
+- [x] `manual-verify` - wasm check

CHANGELOG.md

@@ -28,6 +28,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - **Subagent protocol & UI**: new `AgentEvent::Subagent{Started,Step,ToolCall,Finished}` events, `TimelineItem::SubagentGroup` (tolerant serde for older `sessions.json`), inline subcards with live steps and compact tool-call icons, ~50 ms debounce for parallel event bursts.
 - **Core skills**: embedded harness skills `subagents.md`, `environment.md`, `shell.md`, `git.md`, `web.md` plus updated `file-access.md` / `harness.md` (harness-vs-shell boundary). `system_prompt.rs` skill/tool index expanded with subagent activation triggers.
 - **i18n**: subagent UI states, role display names (Scout / Review / Security Analyst with auto-suffix on conflict), all new tool/environment/shell/git/web labels and the web-disabled hint added to every locale.
+- **Agent chat maximize**: new maximize/minimize icon button in the agent chat header (before Reset). Toggles a compact voice hero (`agent-hero--compact`) inside the Agent right-panel tab only — smaller orb and status line, tagline hidden — so the chat log gains vertical space while Tasks, Context and compose stay visible. Session-local `chat_maximized` state (not persisted per workspace). i18n: `AgChatMaximize`, `AgChatRestore` in all locales.
 
 ### Changed
 

src/i18n/keys.rs

@@ -213,6 +213,8 @@ pub enum I18nKey {
     AgCancel,
     AgResetChat,
     AgResetChatAria,
+    AgChatMaximize,
+    AgChatRestore,
     AgErrNeedPrompt,
     AgYou,
     AgAssistant,

src/i18n/locales/de_de.rs

@@ -238,6 +238,8 @@ Classic: Ctrl+O quick open, Ctrl+` new terminal, Ctrl+Shift+P palette."
         I18nKey::AgResetChatAria => {
             "Clear the chat view and the model conversation history on the server"
         }
+        I18nKey::AgChatMaximize => "Expand chat (minimize voice area)",
+        I18nKey::AgChatRestore => "Restore voice area",
         I18nKey::AgErrNeedPrompt => "Please enter a prompt.",
         I18nKey::AgYou => "You",
         I18nKey::AgAssistant => "Agent",