fix(core,web): retry transport and quota LLM errors, disable dead sessions on auth failure (#82)

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

packages/docs/content/web-app.en.md

@@ -50,7 +50,9 @@ There are four approval modes: `allow-all`, `deny-all`, `read-only` (only read-o
 - Typing `/` opens the slash menu: trigger context compaction (`/compact`) or toggle installed Skills — chosen Skills are sent along with the message in a `[use_skills]` block;
 - While a Task is running the input stays live and the toolbar keeps a single action button: an empty composer shows **Stop**, and typing turns it into **Send**, whose behavior follows the **mid-run send mode** from the toolbar's More-settings popover (a compact extensible settings panel, also available in draft state; the choice is remembered): **Steer** (default) delivers the text mid-run as a `[user_steering]` user message with the next turn, **Queue** holds the whole message server-side as a follow-up and auto-sends it as an ordinary new message when the run finishes (an "N queued" hint shows near the input until then; the queue survives page reloads);
 - Typing `@` mentions another Agent to hand the conversation over to it;
-- When human approval is required, tool calls show inline allow/deny buttons in the message stream; the approval mode can be changed mid-Session.
+- When human approval is required, tool calls show inline allow/deny buttons in the message stream; the approval mode can be changed mid-Session;
+- While the engine waits out a reconnect backoff (≥2s), the retry line shows a live countdown to the next attempt with inline **Retry now** (skips the remaining wait) and **Give up** (the ordinary abort) controls;
+- When the model API rejects the Session's credentials (an authentication failure), the composer grays out and disables — recoverably: the Session pins only the model reference, and credentials come from the current Project config. The notice's primary button opens the Models page; saving a new API key there unlocks the composer by itself (open tabs unlock live via a `credentials_updated` event, and after a reload the composer stays unlocked because the credential update is newer than the recorded auth failure). A "Retry" button clears the state manually for another attempt (it re-arms if the key is still bad), a completed request always clears it, and "New Session" remains as the escape to a fresh draft. The disabled composer keeps its draft selectable, so a long message that failed to send can still be copied out.
 
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