fix: show accurate request status in message footers

Requests could appear to keep working while OpenCode waited to retry, and
retry backoff was described as an active attempt. Report native OpenCode
retry timing, distinguish direct-model backoff from dispatch, and show
preparation, tool activity, pending input, and terminal states accurately.

Keep only the message-footer indicator static. Conversation-list activity
indicators, send/stop controls, retry limits, and command replay behavior
remain unchanged. Align the feature documentation with verified behavior.

Validation: 3618 tests passed, 61 skipped; typecheck and lint passed.
Isolated desktop validation used five real text-model calls across three
profiles, with controlled local fault injection for retry transitions.

Release note: 消息底部现在准确区分请求准备、等待重试、开始重试和需要回答的状态，不再用闪烁暗示仍有进展；会话列表闪点及发送、停止行为保持不变。

FEATURES.md

@@ -251,6 +251,12 @@ otherwise.
   results without reconstructing missing progress.
 - [x] **OpenCode event-stream cleanup**: Each completed or cancelled request
   closes its own subscription without cancelling parallel conversations.
+- [x] **Accurate message-footer status**: Distinguishes request preparation,
+  retry waiting, retry dispatch, tool activity, pending answers, and terminal
+  states. Local OpenCode reports native retry attempts and scheduled times;
+  direct models report their own backoff phase. Footer dots are static, and
+  unsupported Runtime retry details are not invented. Conversation-list
+  indicators and send/stop behavior remain unchanged.
 - [x] **Role-bound model connections**: Each role can inherit the default model
   or select an independent text-model connection. Invalid connections safely
   fall back to the default; the synthesis role always inherits the default.
@@ -432,7 +438,9 @@ otherwise.
   demand or before every response, show zero-result, degraded, failed, and
   cancelled states, and expose cited context or safely open its source.
 - [x] **Magic Notes**: A local-first notes and todo workbench with scope
-  management, editing, filtering, and controlled AI comments. The left
+  management, editing, filtering, and controlled AI comments. The todo view
+  displays the selected item's source entry, with loading, retryable failure,
+  and missing-source feedback. The left
   navigation can show the incomplete-todo count, and create, save, and comment
   results use application-wide notifications.
 - [ ] **MCP Server Control Plane** (planned): Unified MCP lifecycle, health
@@ -449,8 +457,8 @@ otherwise.
   duplicate chat Markdown is hidden from the artifact list but not physically
   deleted. Run history is stored in Main SQLite without the previous 500-item,
   4,000-character, or 2 MB Renderer limits; the page renders it in batches,
-  and a persistent warning remains when a migrated legacy cache may already
-  have lost older records or detail. Token usage is grouped by Runtime and
+  without a persistent legacy-cache truncation warning; previously lost
+  history is not restored. Token usage is grouped by Runtime and
   model and normalizes the different OpenAI-compatible and Anthropic Messages
   cache-reporting semantics when showing cache hit rate. Activity is grouped
   by conversation and collapsed by default so long histories do not fill the