refactor: consolidate experimental chats API types (#23143)

## Summary

Consolidates three areas of type duplication in the experimental chats
API:

### 1. Merge archive/unarchive into `PATCH /{chat}`
- **Before:** `POST /{chat}/archive` + `POST /{chat}/unarchive` (two
endpoints, two handlers with mirrored logic)
- **After:** `PATCH /{chat}` accepting `{ "archived": true/false }` via
`UpdateChatRequest`
- Removes one endpoint and ~30 lines of duplicated handler code

### 2. Collapse identical request/response prompt types
- `ChatSystemPromptResponse` + `UpdateChatSystemPromptRequest` →
`ChatSystemPrompt`
- `UserChatCustomPromptResponse` + `UpdateUserChatCustomPromptRequest` →
`UserChatCustomPrompt`
- These pairs were field-for-field identical (single string field)

### 3. Merge duplicate reasoning options types
- `ChatModelOpenRouterReasoningOptions` +
`ChatModelVercelReasoningOptions` → `ChatModelReasoningOptions`
- Same 4 fields, same types — only field ordering and enum value sets
differed
- Unified type uses the superset of enum values

### Files changed
- `codersdk/chats.go` — SDK types and client methods
- `coderd/chats.go` — Handler consolidation
- `coderd/coderd.go` — Route change
- `coderd/chats_test.go` — Test updates
- `site/src/api/api.ts` — Frontend API client
- `site/src/api/queries/chats.ts` — Query mutations
- `site/src/api/queries/chats.test.ts` — Test mocks
- `site/src/pages/AgentsPage/AgentsPage.tsx` — Call site
- Generated files (`typesGenerated.ts`,
`chatModelOptionsGenerated.json`)

### Testing
- All Go tests pass (`TestArchiveChat`, `TestUnarchiveChat`,
`TestChatSystemPrompt`)
- All frontend tests pass (31/31 in `chats.test.ts`)

coderd/chatd/chatprovider/chatprovider_test.go

@@ -82,7 +82,7 @@ func TestMergeMissingProviderOptions_OpenRouterNested(t *testing.T) {
 
 	options := &codersdk.ChatModelProviderOptions{
 		OpenRouter: &codersdk.ChatModelOpenRouterProviderOptions{
-			Reasoning: &codersdk.ChatModelOpenRouterReasoningOptions{
+			Reasoning: &codersdk.ChatModelReasoningOptions{
 				Enabled: boolPtr(true),
 			},
 			Provider: &codersdk.ChatModelOpenRouterProvider{
@@ -92,7 +92,7 @@ func TestMergeMissingProviderOptions_OpenRouterNested(t *testing.T) {
 	}
 	defaults := &codersdk.ChatModelProviderOptions{
 		OpenRouter: &codersdk.ChatModelOpenRouterProviderOptions{
-			Reasoning: &codersdk.ChatModelOpenRouterReasoningOptions{
+			Reasoning: &codersdk.ChatModelReasoningOptions{
 				Enabled:   boolPtr(false),
 				Exclude:   boolPtr(true),
 				MaxTokens: int64Ptr(123),

coderd/chats.go

@@ -1369,64 +1369,58 @@ func (api *API) watchChatDesktop(rw http.ResponseWriter, r *http.Request) {
 	logger.Debug(ctx, "desktop Bicopy finished")
 }
 
-// EXPERIMENTAL: this endpoint is experimental and is subject to change.
-func (api *API) archiveChat(rw http.ResponseWriter, r *http.Request) {
+// patchChat updates a chat resource. Currently supports toggling the
+// archived state via the Archived field.
+func (api *API) patchChat(rw http.ResponseWriter, r *http.Request) {
 	ctx := r.Context()
 	chat := httpmw.ChatParam(r)
 
-	if chat.Archived {
-		httpapi.Write(ctx, rw, http.StatusBadRequest, codersdk.Response{
-			Message: "Chat is already archived.",
-		})
+	var req codersdk.UpdateChatRequest
+	if !httpapi.Read(ctx, rw, r, &req) {
 		return
 	}
 
-	var err error
-	// Use chatDaemon when available so it can notify
-	// active subscribers. Fall back to direct DB for the
-	// simple archive flag — no streaming state is involved.
-	if api.chatDaemon != nil {
-		err = api.chatDaemon.ArchiveChat(ctx, chat)
-	} else {
-		err = api.Database.ArchiveChatByID(ctx, chat.ID)
-	}
-	if err != nil {
-		httpapi.Write(ctx, rw, http.StatusInternalServerError, codersdk.Response{
-			Message: "Failed to archive chat.",
-			Detail:  err.Error(),
-		})
-		return
-	}
+	if req.Archived != nil {
+		archived := *req.Archived
+		if archived == chat.Archived {
+			state := "archived"
+			if !archived {
+				state = "not archived"
+			}
+			httpapi.Write(ctx, rw, http.StatusBadRequest, codersdk.Response{
+				Message: fmt.Sprintf("Chat is already %s.", state),
+			})
+			return
+		}
 
-	rw.WriteHeader(http.StatusNoContent)
-}
-
-func (api *API) unarchiveChat(rw http.ResponseWriter, r *http.Request) {
-	ctx := r.Context()
-	chat := httpmw.ChatParam(r)
-
-	if !chat.Archived {
-		httpapi.Write(ctx, rw, http.StatusBadRequest, codersdk.Response{
-			Message: "Chat is not archived.",
-		})
-		return
-	}
-
-	var err error
-	// Use chatDaemon when available so it can notify
-	// active subscribers. Fall back to direct DB for the
-	// simple unarchive flag — no streaming state is involved.
-	if api.chatDaemon != nil {
-		err = api.chatDaemon.UnarchiveChat(ctx, chat)
-	} else {
-		err = api.Database.UnarchiveChatByID(ctx, chat.ID)
-	}
-	if err != nil {
-		httpapi.Write(ctx, rw, http.StatusInternalServerError, codersdk.Response{
-			Message: "Failed to unarchive chat.",
-			Detail:  err.Error(),
-		})
-		return
+		var err error
+		// Use chatDaemon when available so it can notify active
+		// subscribers. Fall back to direct DB for the simple
+		// archive flag — no streaming state is involved.
+		if archived {
+			if api.chatDaemon != nil {
+				err = api.chatDaemon.ArchiveChat(ctx, chat)
+			} else {
+				err = api.Database.ArchiveChatByID(ctx, chat.ID)
+			}
+		} else {
+			if api.chatDaemon != nil {
+				err = api.chatDaemon.UnarchiveChat(ctx, chat)
+			} else {
+				err = api.Database.UnarchiveChatByID(ctx, chat.ID)
+			}
+		}
+		if err != nil {
+			action := "archive"
+			if !archived {
+				action = "unarchive"
+			}
+			httpapi.Write(ctx, rw, http.StatusInternalServerError, codersdk.Response{
+				Message: fmt.Sprintf("Failed to %s chat.", action),
+				Detail:  err.Error(),
+			})
+			return
+		}
 	}
 
 	rw.WriteHeader(http.StatusNoContent)
@@ -2525,14 +2519,14 @@ func (api *API) getChatSystemPrompt(rw http.ResponseWriter, r *http.Request) {
 		})
 		return
 	}
-	httpapi.Write(ctx, rw, http.StatusOK, codersdk.ChatSystemPromptResponse{
+	httpapi.Write(ctx, rw, http.StatusOK, codersdk.ChatSystemPrompt{
 		SystemPrompt: prompt,
 	})
 }
 
 func (api *API) putChatSystemPrompt(rw http.ResponseWriter, r *http.Request) {
 	ctx := r.Context()
-	var req codersdk.UpdateChatSystemPromptRequest
+	var req codersdk.ChatSystemPrompt
 	if !httpapi.Read(ctx, rw, r, &req) {
 		return
 	}
@@ -2582,7 +2576,7 @@ func (api *API) getUserChatCustomPrompt(rw http.ResponseWriter, r *http.Request)
 		customPrompt = ""
 	}
 
-	httpapi.Write(ctx, rw, http.StatusOK, codersdk.UserChatCustomPromptResponse{
+	httpapi.Write(ctx, rw, http.StatusOK, codersdk.UserChatCustomPrompt{
 		CustomPrompt: customPrompt,
 	})
 }
@@ -2594,7 +2588,7 @@ func (api *API) putUserChatCustomPrompt(rw http.ResponseWriter, r *http.Request)
 		apiKey = httpmw.APIKey(r)
 	)
 
-	var params codersdk.UpdateUserChatCustomPromptRequest
+	var params codersdk.UserChatCustomPrompt
 	if !httpapi.Read(ctx, rw, r, &params) {
 		return
 	}
@@ -2621,7 +2615,7 @@ func (api *API) putUserChatCustomPrompt(rw http.ResponseWriter, r *http.Request)
 		return
 	}
 
-	httpapi.Write(ctx, rw, http.StatusOK, codersdk.UserChatCustomPromptResponse{
+	httpapi.Write(ctx, rw, http.StatusOK, codersdk.UserChatCustomPrompt{
 		CustomPrompt: updatedConfig.Value,
 	})
 }

coderd/chats_test.go

@@ -29,6 +29,7 @@ import (
 	"github.com/coder/coder/v2/coderd/externalauth"
 	coderdpubsub "github.com/coder/coder/v2/coderd/pubsub"
 	"github.com/coder/coder/v2/coderd/rbac"
+	"github.com/coder/coder/v2/coderd/util/ptr"
 	"github.com/coder/coder/v2/codersdk"
 	"github.com/coder/coder/v2/testutil"
 	"github.com/coder/websocket"
@@ -1687,7 +1688,7 @@ func TestArchiveChat(t *testing.T) {
 		require.NoError(t, err)
 		require.Len(t, chatsBeforeArchive, 2)
 
-		err = client.ArchiveChat(ctx, chatToArchive.ID)
+		err = client.UpdateChat(ctx, chatToArchive.ID, codersdk.UpdateChatRequest{Archived: ptr.Ref(true)})
 		require.NoError(t, err)
 
 		// Default (no filter) returns only non-archived chats.
@@ -1721,7 +1722,7 @@ func TestArchiveChat(t *testing.T) {
 		client := newChatClient(t)
 		_ = coderdtest.CreateFirstUser(t, client)
 
-		err := client.ArchiveChat(ctx, uuid.New())
+		err := client.UpdateChat(ctx, uuid.New(), codersdk.UpdateChatRequest{Archived: ptr.Ref(true)})
 		requireSDKError(t, err, http.StatusNotFound)
 	})
 
@@ -1764,7 +1765,7 @@ func TestArchiveChat(t *testing.T) {
 		require.NoError(t, err)
 
 		// Archive the parent via the API.
-		err = client.ArchiveChat(ctx, parentChat.ID)
+		err = client.UpdateChat(ctx, parentChat.ID, codersdk.UpdateChatRequest{Archived: ptr.Ref(true)})
 		require.NoError(t, err)
 
 		// archived:false should exclude the entire archived family.
@@ -1811,7 +1812,7 @@ func TestUnarchiveChat(t *testing.T) {
 		require.NoError(t, err)
 
 		// Archive the chat first.
-		err = client.ArchiveChat(ctx, chat.ID)
+		err = client.UpdateChat(ctx, chat.ID, codersdk.UpdateChatRequest{Archived: ptr.Ref(true)})
 		require.NoError(t, err)
 
 		// Verify it's archived.
@@ -1822,7 +1823,7 @@ func TestUnarchiveChat(t *testing.T) {
 		require.Len(t, archivedChats, 1)
 		require.True(t, archivedChats[0].Archived)
 		// Unarchive the chat.
-		err = client.UnarchiveChat(ctx, chat.ID)
+		err = client.UpdateChat(ctx, chat.ID, codersdk.UpdateChatRequest{Archived: ptr.Ref(false)})
 		require.NoError(t, err)
 
 		// Verify it's no longer archived.
@@ -1861,10 +1862,9 @@ func TestUnarchiveChat(t *testing.T) {
 		require.NoError(t, err)
 
 		// Trying to unarchive a non-archived chat should fail.
-		err = client.UnarchiveChat(ctx, chat.ID)
+		err = client.UpdateChat(ctx, chat.ID, codersdk.UpdateChatRequest{Archived: ptr.Ref(false)})
 		requireSDKError(t, err, http.StatusBadRequest)
 	})
-
 	t.Run("NotFound", func(t *testing.T) {
 		t.Parallel()
 
@@ -1872,7 +1872,7 @@ func TestUnarchiveChat(t *testing.T) {
 		client := newChatClient(t)
 		_ = coderdtest.CreateFirstUser(t, client)
 
-		err := client.UnarchiveChat(ctx, uuid.New())
+		err := client.UpdateChat(ctx, uuid.New(), codersdk.UpdateChatRequest{Archived: ptr.Ref(false)})
 		requireSDKError(t, err, http.StatusNotFound)
 	})
 }
@@ -4512,7 +4512,7 @@ func TestChatSystemPrompt(t *testing.T) {
 	t.Run("AdminCanSet", func(t *testing.T) {
 		ctx := testutil.Context(t, testutil.WaitLong)
 
-		err := adminClient.UpdateChatSystemPrompt(ctx, codersdk.UpdateChatSystemPromptRequest{
+		err := adminClient.UpdateChatSystemPrompt(ctx, codersdk.ChatSystemPrompt{
 			SystemPrompt: "You are a helpful coding assistant.",
 		})
 		require.NoError(t, err)
@@ -4526,7 +4526,7 @@ func TestChatSystemPrompt(t *testing.T) {
 		ctx := testutil.Context(t, testutil.WaitLong)
 
 		// Unset by sending an empty string.
-		err := adminClient.UpdateChatSystemPrompt(ctx, codersdk.UpdateChatSystemPromptRequest{
+		err := adminClient.UpdateChatSystemPrompt(ctx, codersdk.ChatSystemPrompt{
 			SystemPrompt: "",
 		})
 		require.NoError(t, err)
@@ -4539,7 +4539,7 @@ func TestChatSystemPrompt(t *testing.T) {
 	t.Run("NonAdminFails", func(t *testing.T) {
 		ctx := testutil.Context(t, testutil.WaitLong)
 
-		err := memberClient.UpdateChatSystemPrompt(ctx, codersdk.UpdateChatSystemPromptRequest{
+		err := memberClient.UpdateChatSystemPrompt(ctx, codersdk.ChatSystemPrompt{
 			SystemPrompt: "This should fail.",
 		})
 		requireSDKError(t, err, http.StatusNotFound)
@@ -4560,7 +4560,7 @@ func TestChatSystemPrompt(t *testing.T) {
 		ctx := testutil.Context(t, testutil.WaitLong)
 
 		tooLong := strings.Repeat("a", 131073)
-		err := adminClient.UpdateChatSystemPrompt(ctx, codersdk.UpdateChatSystemPromptRequest{
+		err := adminClient.UpdateChatSystemPrompt(ctx, codersdk.ChatSystemPrompt{
 			SystemPrompt: tooLong,
 		})
 		sdkErr := requireSDKError(t, err, http.StatusBadRequest)

coderd/coderd.go

@@ -1196,8 +1196,7 @@ func New(options *Options) *API {
 				r.Get("/", api.getChat)
 				r.Get("/git/watch", api.watchChatGit)
 				r.Get("/desktop", api.watchChatDesktop)
-				r.Post("/archive", api.archiveChat)
-				r.Post("/unarchive", api.unarchiveChat)
+				r.Patch("/", api.patchChat)
 				r.Get("/messages", api.getChatMessages)
 				r.Post("/messages", api.postChatMessages)
 				r.Patch("/messages/{message}", api.patchChatMessage)