feat: encoding support, tool robustness, history fix, and desktop improvements

desktop/app.go

@@ -615,6 +615,22 @@ type HistoryMessage struct {
 	Role      string `json:"role"`
 	Content   string `json:"content"`
 	Reasoning string `json:"reasoning,omitempty"`
+	// ToolCalls carries the tool calls an assistant message requested. Each
+	// entry mirrors a provider.ToolCall so the frontend can reconstruct tool
+	// cards in historical sessions.
+	ToolCalls []HistoryToolCall `json:"toolCalls,omitempty"`
+	// ToolCallID is set on tool-result messages (role:"tool") so the frontend
+	// can match results back to their dispatch cards.
+	ToolCallID string `json:"toolCallId,omitempty"`
+	// ToolName is set on tool-result messages for display.
+	ToolName string `json:"toolName,omitempty"`
+}
+
+// HistoryToolCall is one tool call from a historical assistant message.
+type HistoryToolCall struct {
+	ID        string `json:"id"`
+	Name      string `json:"name"`
+	Arguments string `json:"arguments"`
 }
 
 // History returns the session's message log.
@@ -640,7 +656,22 @@ func historyMessages(msgs []provider.Message, resolveUserContent func(string) st
 		if m.Role == provider.RoleAssistant {
 			reasoning = m.ReasoningContent
 		}
-		out = append(out, HistoryMessage{Role: string(m.Role), Content: content, Reasoning: reasoning})
+		hm := HistoryMessage{Role: string(m.Role), Content: content, Reasoning: reasoning}
+		// Preserve tool calls from assistant messages so the frontend can
+		// reconstruct tool cards.
+		if m.Role == provider.RoleAssistant && len(m.ToolCalls) > 0 {
+			hm.ToolCalls = make([]HistoryToolCall, len(m.ToolCalls))
+			for i, tc := range m.ToolCalls {
+				hm.ToolCalls[i] = HistoryToolCall{ID: tc.ID, Name: tc.Name, Arguments: tc.Arguments}
+			}
+		}
+		// Preserve tool result linkage so the frontend can fill in tool card
+		// output/errors.
+		if m.Role == provider.RoleTool {
+			hm.ToolCallID = m.ToolCallID
+			hm.ToolName = m.Name
+		}
+		out = append(out, hm)
 	}
 	return out
 }

desktop/frontend/src/components/HistoryPanel.tsx

@@ -285,15 +285,53 @@ function sessionMetaLine(s: SessionMeta, tr: ReturnType<typeof useT>): string {
 }
 
 function previewMessagesToItems(messages: HistoryMessage[]): Item[] {
-  return messages
-    .filter(
-      (m) =>
-        (m.role === "user" && m.content.trim() !== "") ||
-        (m.role === "assistant" && (m.content.trim() !== "" || (m.reasoning ?? "").trim() !== "")),
-    )
-    .map((m, i) =>
-      m.role === "user"
-        ? { kind: "user", id: `hp${i}`, text: m.content }
-        : { kind: "assistant", id: `hp${i}`, text: m.content, reasoning: m.reasoning ?? "", streaming: false },
-    );
+  // Build a lookup: toolCallId → tool result content for filling in tool cards.
+  const resultMap = new Map<string, string>();
+  for (const m of messages) {
+    if (m.role === "tool" && m.toolCallId && !resultMap.has(m.toolCallId)) {
+      resultMap.set(m.toolCallId, m.content);
+    }
+  }
+
+  const items: Item[] = [];
+  let seq = 0;
+  for (const m of messages) {
+    if (m.role === "system" || m.role === "tool") continue;
+    if (m.role === "user") {
+      if (m.content.trim() === "") continue;
+      items.push({ kind: "user", id: `hp${seq}`, text: m.content });
+      seq++;
+      continue;
+    }
+    if (m.role === "assistant") {
+      const hasText = m.content.trim() !== "" || (m.reasoning ?? "").trim() !== "";
+      const toolCalls = m.toolCalls ?? [];
+      if (hasText) {
+        items.push({
+          kind: "assistant",
+          id: `hp${seq}`,
+          text: m.content,
+          reasoning: m.reasoning ?? "",
+          streaming: false,
+        });
+        seq++;
+      }
+      for (const tc of toolCalls) {
+        const output = resultMap.get(tc.id) ?? "";
+        const hasError = output.startsWith("[error") || output.startsWith("Error:");
+        items.push({
+          kind: "tool",
+          id: tc.id || `hpt${seq}`,
+          name: tc.name,
+          args: tc.arguments ?? "",
+          readOnly: false,
+          status: hasError ? "error" : "done",
+          output,
+          error: hasError ? output : undefined,
+        });
+        seq++;
+      }
+    }
+  }
+  return items;
 }

desktop/frontend/src/components/Transcript.tsx

@@ -147,12 +147,16 @@ export function Transcript({
   }, [openTurn]);
 
   // Each user message's turn = its ordinal among user messages, so a rewind
-  // targets the matching checkpoint.
-  const userTurn = new Map<string, number>();
-  let nt = 0;
-  for (const it of items) {
-    if (it.kind === "user") userTurn.set(it.id, nt++);
-  }
+  // targets the matching checkpoint. Memoized so it isn't rebuilt on every
+  // streaming re-render.
+  const userTurn = useMemo(() => {
+    const m = new Map<string, number>();
+    let nt = 0;
+    for (const it of items) {
+      if (it.kind === "user") m.set(it.id, nt++);
+    }
+    return m;
+  }, [items]);
 
   return (
     <div className="transcript" ref={scrollRef} onScroll={onScroll}>

desktop/frontend/src/components/WorkspacePanel.tsx

@@ -40,6 +40,18 @@ const WORKSPACE_PREVIEW_MIN_WIDTH = 420;
 const WORKSPACE_CONTEXT_MENU_FILE_HEIGHT = 92;
 const WORKSPACE_CONTEXT_MENU_REF_HEIGHT = 48;
 
+// Encoding options for the file encoding override selector.
+const ENCODING_OPTIONS = [
+  { value: "", label: "Auto" },
+  { value: "UTF-8", label: "UTF-8" },
+  { value: "UTF-8 BOM", label: "UTF-8 BOM" },
+  { value: "GB18030", label: "GB18030" },
+  { value: "UTF-16 LE", label: "UTF-16 LE" },
+  { value: "UTF-16 BE", label: "UTF-16 BE" },
+  { value: "UTF-16 LE (no BOM)", label: "UTF-16 LE (no BOM)" },
+  { value: "UTF-16 BE (no BOM)", label: "UTF-16 BE (no BOM)" },
+] as const;
+
 function clampWorkspaceTreeWidth(width: number, panelWidth?: number): number {
   const maxForPanel =
     typeof panelWidth === "number" && Number.isFinite(panelWidth)
@@ -187,6 +199,18 @@ export function WorkspacePanel({
   const [treeVisible, setTreeVisible] = useState(true);
   const [treeWidth, setTreeWidth] = useState(loadWorkspaceTreeWidth);
   const [treeResizing, setTreeResizing] = useState(false);
+  const [projectEncoding, setProjectEncoding] = useState<string>("");
+
+  // Load project encoding from settings on panel open / workspace change.
+  useEffect(() => {
+    if (!open) return;
+    app.Settings().then((s) => setProjectEncoding(s.fileEncoding || "")).catch(() => {});
+  }, [cwd, open]);
+
+  const changeProjectEncoding = useCallback(async (enc: string) => {
+    setProjectEncoding(enc);
+    await app.SetFileEncoding(enc).catch(() => {});
+  }, []);
 
   const loadDir = useCallback(async (dir: string) => {
     const entries = await app.ListDir(dir).catch(() => []);
@@ -267,7 +291,7 @@ export function WorkspacePanel({
     let live = true;
     setLoadingPreview(true);
     app
-      .ReadFile(selectedPath)
+      .ReadFile(selectedPath, projectEncoding || "")
       .then((next) => {
         if (live) setPreview(next);
       })
@@ -289,7 +313,7 @@ export function WorkspacePanel({
     return () => {
       live = false;
     };
-  }, [selectedPath]);
+  }, [selectedPath, projectEncoding]);
 
   useEffect(() => {
     if (!open || !selectedPath) return;
@@ -496,7 +520,7 @@ export function WorkspacePanel({
     const target = treeMenu;
     setTreeMenu(null);
     try {
-      const file = await app.ReadFile(target.path);
+      const file = await app.ReadFile(target.path, "");
       if (file.err || file.binary) {
         onAddToChat?.(formatWorkspaceReference(target.path, false));
         return;
@@ -776,6 +800,20 @@ export function WorkspacePanel({
               <RefreshCw size={14} />
             </button>
           </Tooltip>
+          <Tooltip label={t("workspace.encodingOverride")}>
+            <select
+              className="workspace-encoding-select"
+              value={projectEncoding}
+              onChange={(e) => void changeProjectEncoding(e.target.value)}
+              title={projectEncoding ? t("workspace.encodingTitle").replace("{enc}", projectEncoding) : t("workspace.encoding")}
+            >
+              {ENCODING_OPTIONS.map((opt) => (
+                <option key={opt.value} value={opt.value}>
+                  {opt.value === "" ? t("workspace.encodingAuto") : opt.label}
+                </option>
+              ))}
+            </select>
+          </Tooltip>
         </div>
 
         <div className="workspace-search">

desktop/frontend/src/lib/bridge.ts

@@ -101,7 +101,7 @@ export interface AppBindings {
   SlashArgs(input: string): Promise<SlashArgsResult>;
   ListDir(rel: string): Promise<DirEntry[]>;
   SearchFileRefs(query: string): Promise<DirEntry[]>;
-  ReadFile(rel: string): Promise<FilePreview>;
+  ReadFile(rel: string, enc?: string): Promise<FilePreview>;
   WorkspaceChanges(): Promise<WorkspaceChangesView>;
   OpenWorkspacePath(rel: string): Promise<void>;
   RevealWorkspacePath(rel: string): Promise<void>;
@@ -139,6 +139,8 @@ export interface AppBindings {
   // SetBypass toggles YOLO mode (auto-approve every tool call this session; deny
   // rules still apply). Runtime-only — not written to config.
   SetBypass(on: boolean): Promise<void>;
+  // SetFileEncoding sets the project-level file encoding for read/write tools.
+  SetFileEncoding(encoding: string): Promise<void>;
   // Auto-updater (desktop/updater_app.go): the injected build version, a manifest
   // check, applying an update (win/linux self-update; macOS opens the download
   // page), and opening that page directly. Progress streams on "updater:progress".
@@ -392,6 +394,7 @@ function makeMockApp(): AppBindings {
     configPath: "~/projects/reasonix/reasonix.toml",
     providerKinds: ["openai"],
     bypass: false,
+    fileEncoding: "UTF-8",
   };
   return {
     async Platform() {
@@ -789,7 +792,7 @@ function makeMockApp(): AppBindings {
         .filter((path) => path.split("/").pop()?.toLowerCase().includes(q))
         .map((name) => ({ name, isDir: false }));
     },
-    async ReadFile(rel: string) {
+    async ReadFile(rel: string, _enc?: string) {
       const samples: Record<string, string> = {
         "README.md": "# Reasonix\n\nBrowser-dev workspace preview.\n\n- Chat in the center\n- Browse files on the right\n- Keep sessions on the left\n",
         "go.mod": "module reasonix\n\ngo 1.23\n",
@@ -940,6 +943,9 @@ function makeMockApp(): AppBindings {
     async SetBypass(on: boolean) {
       settings.bypass = on;
     },
+    async SetFileEncoding(encoding: string) {
+      settings.fileEncoding = encoding;
+    },
     async Version() {
       return "v1.0.0 (browser dev)";
     },

desktop/frontend/src/lib/types.ts

@@ -45,26 +45,13 @@ export interface WireUsage {
   cacheHitTokens: number;
   cacheMissTokens: number;
   reasoningTokens?: number;
-  cacheDiagnostics?: WireCacheDiagnostics;
   // Session-cumulative cache tokens — the status bar shows the aggregate
   // hit-rate (Σhit/Σ(hit+miss)), steadier than the single-turn cacheHitTokens.
   sessionCacheHitTokens: number;
   sessionCacheMissTokens: number;
   costUsd?: number;
 }
 
-export interface WireCacheDiagnostics {
-  prefixHash: string;
-  prefixChanged: boolean;
-  prefixChangeReasons?: string[];
-  systemHash: string;
-  toolsHash: string;
-  logRewriteVersion: number;
-  toolSchemaTokens: number;
-  cacheMissTokens: number;
-  cacheHitTokens: number;
-}
-
 export interface WireApproval {
   id: string;
   tool: string;
@@ -115,6 +102,15 @@ export interface HistoryMessage {
   role: string;
   content: string;
   reasoning?: string;
+  toolCalls?: HistoryToolCall[];
+  toolCallId?: string;
+  toolName?: string;
+}
+
+export interface HistoryToolCall {
+  id: string;
+  name: string;
+  arguments: string;
 }
 
 // CheckpointMeta is one rewind point (a user turn) for the rewind UI.
@@ -406,6 +402,7 @@ export interface SettingsView {
   configPath: string;
   providerKinds: string[]; // provider implementations the kernel registered (for the kind picker)
   bypass: boolean; // live YOLO state (runtime-only) — whether approvals are skipped this session
+  fileEncoding: string; // project-level file encoding (e.g. "UTF-8", "GB18030")
 }
 
 // Auto-updater payloads (desktop/updater.go). UpdateInfo drives the update banner;