## Summary
This change removes the steady-state "resolve the latest workspace
agent" query from chat execution.
Instead of asking the database for the latest build's agent on every
turn, a chat now persists the workspace/build/agent binding it actually
uses and reuses that binding across subsequent turns. The common path
becomes "load the bound agent by ID and dial it", with fallback paths to
repair the binding when it is missing, stale, or intentionally changed.
## What changes
- add `workspace_id`, `build_id`, and `agent_id` binding fields to
`chats`
- expose those fields through the chat API / SDK so the execution
context is explicit
- load the persisted binding first in chatd, instead of always resolving
the latest build's agent
- persist a refreshed binding when chatd has to re-resolve the workspace
agent
- keep child / subagent chats on the same bound workspace context by
inheriting the parent binding
- leave `build_id` / `agent_id` unset for flows like `create_workspace`,
then bind them lazily on the next agent-backed turn
## Runtime behavior
The binding is treated as an optimistic cache of the agent a chat should
use:
- if the bound agent still exists and dials successfully, we use it
without a latest-build lookup
- if the bound agent is missing or no longer reachable, chatd
re-resolves against the latest build and persists the new binding
- if a workspace mutation changes the chat's target workspace, the
binding is updated as part of that mutation
To avoid reintroducing a hot-path query, dialing uses lazy validation:
- start dialing the cached agent immediately
- only validate against the latest build if the dial is still pending
after a short delay
- if validation finds a different agent, cancel the stale dial, switch
to the current agent, and persist the repaired binding
## Result
The hot path stops issuing
`GetWorkspaceAgentsInLatestBuildByWorkspaceID` for every user message,
which is the source of the DB pressure this PR is addressing. At the
same time, chats still converge to the correct workspace agent when the
binding becomes stale due to rebuilds or explicit workspace changes.
Previously, long bash commands in the execute tool were truncated with
an ellipsis and could not be viewed in full. The only way to see the
full command was to copy it via the copy button.
Adds overflow detection and an inline expand/collapse chevron next to
the copy button. Clicking the command text or the chevron toggles
between truncated and wrapped views. Short commands that fit on one line
are visually unchanged.
https://github.com/user-attachments/assets/88ec6cd4-5212-4608-9a90-9ce217d5dce7
EDIT: couldn't be bothered re-recording the video but the chevron is
hidden until hovered now, like the copy button.
_PR generated by Mux but reviewed by a human_
## Problem
The e2e test `template update with new name redirects on successful
submit` is flaky.
After saving template settings, the app navigates to
`/templates/<name>`, which immediately redirects to
`/templates/<name>/docs` via the router's index route (`<Navigate
to="docs" replace />`). The assertion used `expect.poll()` with
`toHavePathNameEndingWith(`/${name}`)`, which matches only the
**transient intermediate URL** — it only exists while `TemplateLayout`'s
async data fetch is pending. Once the fetch resolves and the `<Outlet
/>` renders, the index route fires the `/docs` redirect and the URL no
longer matches.
## Why it's flaky (not deterministic)
The flakiness depends on whether the template query cache is warm:
- **Cache miss → PASSES**: The mutation's `onSuccess` handler
invalidates the query cache. If `TemplateLayout` needs to re-fetch, it
shows a `<Loader />`, which delays rendering the `<Outlet />` that
contains the `<Navigate to="docs">`. This gives `expect.poll()` time to
see the transient `/new-name` URL → **pass**.
- **Cache hit → FAILS**: If the template data is still in the query
client, `TemplateLayout` renders immediately and the `<Navigate
to="docs" replace />` fires nearly instantly. By the time the first poll
runs, the URL is already `/new-name/docs` → **fail**.
## Fix
Assert the **final stable URL** (`/${name}/docs`) instead of the
transient one.
This is safe because `expect.poll()` is retry-based: it keeps sampling
until a match is found (or timeout). Seeing the transient `/new-name`
URL just causes harmless retries — once the redirect completes and the
URL settles on `/new-name/docs`, the poll matches and the test passes.
| Poll | URL | Ends with `/new-name/docs`? | Action |
|---|---|---|---|
| 1st | `/templates/new-name` | No | Retry |
| 2nd | `/templates/new-name` | No | Retry |
| 3rd | `/templates/new-name/docs` | Yes | **Pass** ✅ |
Closes https://github.com/coder/internal/issues/1403
The `/agents` model picker collapsed distinct configured model variants
into fewer entries because options were built from the deduplicated
catalog (`ChatModelsResponse`). Two configs with the same provider/model
but different display names or settings appeared as a single option.
Switch option building from `getModelOptionsFromCatalog()` to a new
`getModelOptionsFromConfigs()` that emits one `ModelSelectorOption` per
enabled `ChatModelConfig` row. The option ID is the config UUID
directly, eliminating the catalog-ID ↔ config-ID mapping layer
(`buildModelConfigIDByModelID`, `buildModelIDByConfigID`).
Provider availability is still gated by the catalog response, and status
messaging ("no models configured" vs "models unavailable") is unchanged.
The sidebar now resolves model labels by config ID first, and the
/agents Storybook fixtures were updated so the stories seed matching
config IDs and model-config query data after the picker contract change.
The `/agents` transcript used `flex-col-reverse` for bottom-anchored
chat layout, where `scrollTop = 0` means bottom and the sign of
`scrollTop` when scrolled up varies by browser engine. A
`ResizeObserver` detected content height changes and applied manual
`compensateScroll(delta)` to preserve position, which fought manual
upward scrolling during streaming — repeatedly adjusting the user's
scroll position when they were trying to read earlier content.
This replaces that model with normal DOM order (`flex-col`, standard
`overflow-y: auto`) and a dedicated `useAgentTranscriptAutoScroll` hook
that only auto-scrolls when follow-mode is enabled. When the user
scrolls up, follow-mode disables and incoming content does not move the
viewport.
Changes:
- **New**: `useAgentTranscriptAutoScroll.ts` — local hook with
follow-mode state, RAF-throttled button visibility, dual
`ResizeObserver` (content + container), and `jumpToBottom()`
- **Modified**: `AgentDetailView.tsx` — removed
`ScrollAnchoredContainer` (~350 lines of reverse-layout compensation),
replaced with normal-order container wired to the new hook, added
pagination prepend scroll restoration
- **Modified**: `AgentDetailView.stories.tsx` — updated scroll stories
for normal-order bottom-distance assertions
## Summary
Tool call failures in `/agents` previously displayed alarming red
styling (red icons, red text, red alert icons) that made it look like
the user did something wrong. This PR replaces the scary error
presentation with a calm, unified style and adds a dedicated timeout
display for subagent tools.
## Changes
### Unified failure style (all tools)
- Replace red `CircleAlertIcon` + `text-content-destructive` with a
muted `TriangleAlertIcon` in `text-content-secondary` across **all 11
tool renderers**.
- Remove red icon/label recoloring on error from `ToolIcon` and all
specialized tool components.
- Error details remain accessible via tooltip on hover.
### Subagent timeout display
- `ClockIcon` with "Timed out waiting for [Title]" instead of a generic
error display.
- `CircleXIcon` for non-timeout subagent errors with proper error verbs
("Failed to spawn", "Failed waiting for", etc.) instead of the
misleading running verb ("Waiting for").
- Timeout detection from result string/error field containing "timed
out".
### Title resolution for historical messages
- `ConversationTimeline` now computes `subagentTitles` via
`useMemo(buildSubagentTitles(...))` and passes it to historical
`ChatMessageItem` rendering, so `wait_agent` can resolve the actual
agent title from a prior `spawn_agent` result even outside streaming
mode.
### Stories
8 new stories: `GenericToolFailed`, `GenericToolFailedNoResult`,
`SubagentWaitTimedOut`, `SubagentWaitTimedOutWithTitle`,
`SubagentWaitTimedOutTitleFromMap`, `SubagentSpawnError`,
`SubagentWaitError`, `MCPToolFailedUnifiedStyle`.
## Files changed (15)
- `tool/Tool.tsx` — GenericToolRenderer + SubagentRenderer
- `tool/SubagentTool.tsx` — timeout/error verbs, icon changes
- `tool/ToolIcon.tsx` — remove destructive recoloring
- `tool/*.tsx` (10 specialized tools) — unified warning icon
- `ConversationTimeline.tsx` — pass subagentTitles to historical
rendering
- `tool.stories.tsx` — 8 new stories, updated existing assertions
## Summary
Adds a general-purpose `map[string]string` label system to chats, stored
as jsonb with a GIN index for efficient containment queries.
This is a standalone foundational feature that will be used by the
upcoming Automations feature for session identity (matching webhook
events to existing chats), replacing the need for bespoke session-key
tables.
## Changes
### Database
- **Migration 000451**: Adds `labels jsonb NOT NULL DEFAULT '{}'` column
to `chats` table with a GIN index (`idx_chats_labels`)
- **`InsertChat`**: Accepts labels on creation via `COALESCE(@labels,
'{}')`
- **`UpdateChatByID`**: Supports partial update —
`COALESCE(sqlc.narg('labels'), labels)` preserves existing labels when
NULL is passed
- **`GetChats`**: New `has_labels` filter using PostgreSQL `@>`
containment operator
- **`GetAuthorizedChats`**: Synced with generated `GetChats` (new column
scan + query param)
### API
- **Create chat** (`POST /chats`): Accepts optional `labels` field,
validated before creation
- **Update chat** (`PATCH /chats/{chat}`): Supports `labels` field for
atomic label replacement
- **List chats** (`GET /chats`): Supports `?label=key:value` query
parameters (multiple are AND-ed)
### SDK
- `Chat`, `CreateChatRequest`, `UpdateChatRequest`, `ListChatsOptions`
all gain `Labels` fields
- `UpdateChatRequest.Labels` is a pointer (`*map[string]string`) so
`nil` means "don't change" vs empty map means "clear all"
### Validation (`coderd/httpapi/labels.go`)
- Max 50 labels per chat
- Key: 1–64 chars, must match `[a-zA-Z0-9][a-zA-Z0-9._/-]*` (supports
namespaced keys like `github.repo`, `automation/pr-number`)
- Value: 1–256 chars
- 13 test cases covering all edge cases
### Chat runtime
- `chatd.CreateOptions` gains `Labels` field, threaded through to
`InsertChat`
- Existing `UpdateChatByID` callers (e.g., quickgen title updates) are
unaffected — NULL labels preserve existing values via COALESCE
We had a bug where computer use base64-encoded screenshots would not be
interpreted as screenshots anymore once saved to the db, loaded back
into memory, and sent to Anthropic. Instead, they would be interpreted
as regular text. Once a computer use agent made enough screenshots and
stopped, and you tried sending it another message, you'd get an out of
context error:
<img width="808" height="367" alt="Screenshot 2026-03-23 at 12 02 54"
src="https://github.com/user-attachments/assets/f0bf6be2-4863-47ca-a7a9-9e6d9dfceeed"
/>
This PR fixes that.
## Summary
Introduces a new `context-file` ChatMessagePart type for persisting
workspace instruction files (AGENTS.md) as durable, frontend-visible
message parts. This is the foundation for showing loaded context files
in the chat input's context indicator tooltip.
### Problem
Previously, instruction files were resolved transiently on every turn
via `resolveInstructions()` → `InsertSystem()` and injected into the
in-memory prompt without persistence. The frontend had no knowledge that
instruction files were loaded into context, and there was no way to
surface this information to users.
### Solution
Instruction files are now read **once** when a workspace is first
attached to a chat (matching how [openai/codex handles
it](https://developers.openai.com/codex/guides/agents-md)) and persisted
as `user`-role, `both`-visibility message parts with a new
`context-file` type. This ensures:
- **Durability**: survives page refresh (data is in the DB, returned by
`getChatMessages`)
- **Cache-friendly**: `user`-role avoids the system-message hoisting
that providers do, keeping the instruction content in a stable position
for prompt caching
- **Frontend-visible**: the frontend receives paths and truncation
status for future context indicator rendering
- **Extensible**: the same pattern works for Skills (future)
### Key changes
| Layer | Change |
|---|---|
| **SDK** (`codersdk/chats.go`) | Add `ChatMessagePartTypeContextFile`
with `context_file_path`, `context_file_content` (internal, stripped
from API), `context_file_truncated` fields |
| **Prompt expansion** (`chatprompt`) | Expand `context-file` parts to
`<workspace-context>` text blocks in `partsToMessageParts()` |
| **Chat engine** (`chatd.go`) | Add `persistInstructionFiles()`, called
on first turn with a workspace. Remove per-turn `resolveInstructions()`
+ `InsertSystem()` from `processChat()` and `ReloadMessages` |
| **Frontend** | Ignore `context-file` parts in `messageParsing.ts` and
`streamState.ts` (no rendering yet — follow-up will add tooltip display)
|
### How it works
1. On each turn, `processChat` checks if any loaded message contains
`context-file` parts
2. If not (first turn with a workspace), reads AGENTS.md files via the
workspace agent connection and persists them
3. For this first turn, also injects the instruction text into the
prompt (since messages were loaded before persistence)
4. On all subsequent turns, `ConvertMessagesWithFiles()` encounters the
persisted `context-file` parts and expands them into text automatically
— no extra resolution needed
The description read "Control access of templates for users and groups
to templates" with "templates" appearing twice and garbled grammar.
Simplified to "Control user and group access to templates."
---------
Co-authored-by: Jake Howell <jacob@coder.com>
HealthLayout sets refetchInterval: 30_000 on its health query.
In storybook tests, the seeded cache data prevents the initial
fetch, but interval polling still fires after 30s, hitting the
Vite proxy with no backend. This caused test-storybook to hang
indefinitely in environments without a running coderd.
Set refetchInterval: false in the storybook QueryClient defaults
alongside the existing staleTime: Infinity and retry: false.
- Stores a deployment-wide agents template allowlist in `site_configs`
(`agents_template_allowlist`)
- Adds `GET/PUT /api/experimental/chats/config/template-allowlist`
endpoints
- Filters `list_templates`, `read_template`, and `create_workspace` chat
tools by allowlist, if defined (empty=all allowed)
- Add "Templates" admin settings tab in Agents UI ([what it looks
like](https://624de63c6aacee003aa84340-sitjilsyrr.chromatic.com/?path=/story/pages-agentspage-agentsettingspageview--template-allowlist))
> 🤖 This PR was created with the help of Coder Agents, and has been
reviewed by my human. 🧑💻
> **PR Stack**
>
> 1. #23351 ← `#23282`
> 2. **#23282** ← `#23275` *(you are here)*
> 3. #23275 ← `#23349`
> 4. #23349 ← `main`
---
## Summary
Replaces raw error strings and infinite "Thinking..." spinners in the
agents chat UI with a structured live-status model that drives startup,
retry, and failure UI from one source of truth.
This branch also folds in the frontend follow-up fixes that fell out of
that refactor: malformed `retrying_at` timestamps no longer render
`Retrying in NaNs`, stale persisted generic errors no longer outlive a
recovered chat status, and partial streamed output stays visible when a
response fails after blocks have already rendered.
Consumes the structured error metadata added in #23275.
Retry-After header handling remains in #23351.
<img width="853" height="493" alt="image"
src="https://github.com/user-attachments/assets/5a4a1690-5e22-4ece-965c-a000fd669244"
/>
<img width="812" height="517" alt="image"
src="https://github.com/user-attachments/assets/e78d28ce-1566-48ca-a991-62c6e1838079"
/>
<img width="847" height="523" alt="image"
src="https://github.com/user-attachments/assets/e5fd7b60-4a3c-4573-ba4c-4e5f6dbfbdc3"
/>
## Problem
The previous AgentDetail chat UI derived startup, retry, and failure
behavior from several loosely connected bits of state spread across
`ChatContext`, `AgentDetailContent`, `ConversationTimeline`, and ad hoc
props. That made the UI inconsistent: some failures were just raw
strings, retry state could only partially describe what was happening,
startup could sit on an infinite spinner, and rendering decisions
depended on local booleans instead of one authoritative model.
Those splits also made edge cases brittle. Invalid retry timestamps
could produce broken countdown text, persisted generic errors could
linger after recovery, and streamed partial output could disappear if
the turn later failed.
## Fix
Introduce a structured live-status pipeline for AgentDetail.
`ChatContext` now normalizes stream errors and retry metadata into
richer state, `liveStatusModel` centralizes precedence and phase
derivation, and `ChatStatusCallout` renders startup, retry, and terminal
failure states with shared copy, provider attribution, status links,
attempt metadata, and guarded countdown handling.
`AgentDetailContent` and `ConversationTimeline` now consume that single
model instead of juggling separate error and stream booleans, while
usage-limit messaging stays on its explicit path. The result is a
timeline that shows consistent state transitions, preserves accumulated
assistant output across failures, suppresses stale generic errors once
live state recovers, and has focused model, store, and story coverage
around those behaviors.
## Problem
Text attachments (`InlineTextAttachmentButton`) and image thumbnails
(`ImageThumbnail`) rendered at different heights when displayed side by
side in user messages. Text cards had no explicit height
(content-driven), while images used `h-16` (64px).
## Changes
**`ConversationTimeline.tsx`**
- Added `h-16` to `InlineTextAttachmentButton` to match `ImageThumbnail`
- Added `isPlaceholder` prop: when the content hasn't been fetched yet
(file_id path), renders "Pasted text" in sans-serif `text-sm` with
`items-center` alignment instead of monospace `text-xs`
- Once real content loads, it still renders in `font-mono text-xs` with
`formatTextAttachmentPreview()`
**`ConversationTimeline.stories.tsx`**
- Added `UserMessageWithMixedAttachments` story showing a text
attachment and image side by side as a visual regression guard
When a chat is created, createChat.onSuccess invalidates the sidebar
list query, triggering a background refetch. The refetch can hit the
server before async title generation finishes, returning the fallback
(truncated) title. If the title_change WebSocket event arrives and
writes the generated title into the cache, the in-flight refetch
response then overwrites it with the stale fallback title.
Cancel any in-flight sidebar-list and per-chat refetches before every
WebSocket-driven cache write. This mirrors the existing pattern in
archiveChat/unarchiveChat, which cancel queries before optimistic
updates for the same reason.
- Add `SanitizePromptText` stripping ~24 invisible Unicode codepoints
and collapsing excessive newlines
- Apply at write and read paths for defense-in-depth
- Frontend: warn in both prompt textareas when invisible characters
detected
- Explicit codepoint list (not blanket `unicode.Cf`) to avoid breaking
flag emoji
- 34 Go tests + idempotency meta-test, 11 TS unit tests, 4 Storybook
stories
> This PR was created with the help of Coder Agents, and was reviewed by my human.
## Changes
Replaces the "Loading model catalog..." / "Loading models..." text flash
on `/agents` with a clean skeleton loading state, and removes the
admin-nag status messages entirely.
### Removed
- `getModelCatalogStatusMessage()` function and
`modelCatalogStatusMessage` prop chain — "Loading model catalog..." /
"No chat models are configured. Ask an admin to configure one." text
below the input
- `inputStatusText` prop chain — "No models configured. Ask an admin." /
"Models are configured but unavailable. Ask an admin." inline text
- `modelCatalogError` prop from `AgentCreateForm`
### Changed
- `AgentChatInput`: when `isModelCatalogLoading` is true, renders a
`Skeleton` in place of the `ModelSelector`
- `getModelSelectorPlaceholder()`: "No Models Configured" / "No Models
Available" (title case)
### Added
- `LoadingModelCatalog` story — skeleton where model selector sits
- `NoModelsConfigured` story — selector shows "No Models Configured"
Net -69 lines.
## Problem
The sticky user message visual state (`--clip-h`, fade gradient, push-up
positioning) is driven by an `update()` function that only ran on
`scroll` events. The chat scroll container uses `flex-col-reverse`,
where `scrollTop = 0` means "at bottom." When streaming content grows
the transcript while the user is auto-scrolled to the bottom,
`scrollTop` stays at `0` — no `scroll` event fires — so `update()` never
runs and the sticky messages become visually stale until the user
manually scrolls.
## Fix
Add a `ResizeObserver` on the scroller's content wrapper inside the
existing `useLayoutEffect` that sets up the scroll/resize listeners.
When the content wrapper resizes (streaming growth), it fires the
observer which calls `update()` through the same RAF-throttle pattern
used by the scroll handler.
Single observer per sticky message instance. Zero cost when nothing is
resizing. Cleanup handled in the same effect teardown.
Wraps the `GenericToolRenderer` (used for MCP and unrecognized tools) in
`ToolCollapsible` so the result content is hidden behind a
click-to-expand chevron, matching the pattern used by `read_file`,
`write_file`, and other built-in tool renderers.
### Changes
- Move `ToolIcon` + `ToolLabel` into the `ToolCollapsible` `header` prop
- Compute `hasContent` from `writeFileDiff` / `fileContent` /
`resultOutput` — when there's no content, the header renders as a plain
div with no chevron
- Remove `ml-6` from `ScrollArea` classNames (the `ToolCollapsible`
button handles its own layout)
- `defaultExpanded` is `false` by default in `ToolCollapsible`, so
results start collapsed
### Before
MCP tool results were always fully visible inline.
### After
MCP tool results are collapsed by default with a chevron toggle,
consistent with `read_file`, `edit_files`, `list_templates`, etc.
## Summary
Previously the user's MCP server toggles were ephemeral — every page
reload or navigation to a new chat reset them to the admin-configured
defaults (`force_on` + `default_on`). This was frustrating for users who
routinely disabled a default-on server or enabled a default-off one.
This PR persists the MCP server picker selection to `localStorage` under
the key `agents.selected-mcp-server-ids`.
## Changes
### `MCPServerPicker.tsx`
- **`mcpSelectionStorageKey`** — exported constant for the localStorage
key.
- **`getSavedMCPSelection(servers)`** — reads from localStorage, filters
out stale/disabled IDs, always includes `force_on` servers.
- **`saveMCPSelection(ids)`** — writes the current selection to
localStorage.
### `AgentCreateForm.tsx`
- Initialises `userMCPServerIds` from `getSavedMCPSelection` instead of
`null`.
- Calls `saveMCPSelection` on every toggle.
### `AgentDetail.tsx`
- Adds localStorage as a fallback tier in `effectiveMCPServerIds`: user
override → chat record → **saved selection** → defaults.
- Calls `saveMCPSelection` on every toggle.
### `MCPServerPicker.test.ts` (new)
- 13 unit tests covering save, restore, stale-ID filtering, force_on
merging, invalid JSON handling, and disabled server filtering.
## Fallback priority
| Priority | Source | When |
|----------|--------|------|
| 1 | In-memory state | User toggled during this session |
| 2 | Chat record | Existing conversation with `mcp_server_ids` |
| 3 | localStorage | User has a saved selection from a prior session |
| 4 | Server defaults | `force_on` + `default_on` servers |
## Description
When duplicating a template that has prebuilds configured, a warning
alert is now shown above the create template form. The warning displays
the total number of prebuilds that will be automatically created.
### Changes
**Single file modified:**
`site/src/pages/CreateTemplatePage/DuplicateTemplateView.tsx`
- Fetches presets for the template's active version using the existing
`templateVersionPresets` React Query helper
- Computes total prebuild count by summing `DesiredPrebuildInstances`
across all presets
- Renders a warning `<Alert>` above the form when prebuilds are
configured
### Design decisions
| Decision | Rationale |
|---|---|
| Warning in `DuplicateTemplateView`, not `CreateTemplateForm` | Only
the duplicate flow needs this. Keeps data fetching local. No new props.
|
| Feature-flag gated (`workspace_prebuilds`) | Matches existing pattern
in `TemplateLayout.tsx`. |
| Non-blocking query | Presets fetch failure shouldn't prevent
duplication. Warning is informational. |
| Count with pluralization | Users know exactly how many prebuilds will
spin up. |
<img width="1136" height="375" alt="image"
src="https://github.com/user-attachments/assets/1ca42608-a204-48f5-b27d-6d476ab32fa7"
/>
Closes#18987
> **PR Stack**
> 1. #23351 ← `#23282`
> 2. #23282 ← `#23275`
> 3. **#23275** ← `#23349` *(you are here)*
> 4. #23349 ← `main`
---
## Summary
Extracts a structured error classification subsystem for agent chat
(`chatd`) so that retry and error payloads carry machine-readable
metadata — error kind, provider name, HTTP status code, and retryability
— instead of raw error strings.
This is the **backend half** of the error-handling work. The frontend
counterpart is in #23282.
## Changes
### New package: `coderd/chatd/chaterror/`
Canonical error classification — extracts error kind, provider, status
code, and user-facing message from raw provider errors. One source of
truth that drives both retry policy and stream payloads.
- **`kind.go`**: Error kind enum (`rate_limit`, `timeout`, `auth`,
`config`, `overloaded`, `unknown`).
- **`signals.go`**: Signal extraction — parses provider name, HTTP
status code, and retryability from error strings and wrapped types.
- **`classify.go`**: Classification logic — maps extracted signals to an
error kind.
- **`message.go`**: User-facing message templates keyed by kind +
signals.
- **`payload.go`**: Projectors that build `ChatStreamError` and
`ChatStreamRetry` payloads from a classified error.
### Modified
- **`codersdk/chats.go`**: Added `Kind`, `Provider`, `Retryable`,
`StatusCode` fields to `ChatStreamError` and `ChatStreamRetry`.
- **`coderd/chatd/chatretry/`**: Thinned to retry-policy only;
classification logic moved to `chaterror`.
- **`coderd/chatd/chatloop/`**: Added per-attempt first-chunk timeout
(60 s) via `guardedStream` wrapper — produces retryable
`startup_timeout` errors instead of hanging forever.
- **`coderd/chatd/chatd.go`**: Publishes normalized retry/error payloads
via `chaterror` projectors.
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Adds the AI Bridge sessions list page.
Ethan