fix(messages): handle encoded href paths and tighten relative link detection

Author: Samigos

src/features/messages/components/Markdown.tsx

@@ -268,13 +268,12 @@ function isLikelyFileHref(url: string) {
   if (hasLikelyFileName(trimmed)) {
     return true;
   }
-  if (
-    trimmed.startsWith("~/") ||
-    trimmed.startsWith("./") ||
-    trimmed.startsWith("../")
-  ) {
+  if (trimmed.startsWith("~/")) {
     return true;
   }
+  if (trimmed.startsWith("./") || trimmed.startsWith("../")) {
+    return FILE_LINE_SUFFIX_PATTERN.test(trimmed) || hasLikelyFileName(trimmed);
+  }
   return false;
 }
 
@@ -608,7 +607,7 @@ export function Markdown({
     if (isLikelyFileHref(url)) {
       const directPath = getLinkablePath(url);
       if (directPath) {
-        return directPath;
+        return safeDecodeURIComponent(directPath) ?? directPath;
       }
     }
     const decodedUrl = safeDecodeURIComponent(url);

src/features/messages/components/Messages.test.tsx

@@ -261,6 +261,31 @@ describe("Messages", () => {
     expect(openFileLinkMock).toHaveBeenCalledWith(linkedPath);
   });
 
+  it("decodes percent-encoded href file paths before opening", () => {
+    const items: ConversationItem[] = [
+      {
+        id: "msg-file-href-encoded-link",
+        kind: "message",
+        role: "assistant",
+        text: "Open [guide](./docs/My%20Guide.md)",
+      },
+    ];
+
+    render(
+      <Messages
+        items={items}
+        threadId="thread-1"
+        workspaceId="ws-1"
+        isThinking={false}
+        openTargets={[]}
+        selectedOpenAppId=""
+      />,
+    );
+
+    fireEvent.click(screen.getByText("guide"));
+    expect(openFileLinkMock).toHaveBeenCalledWith("./docs/My Guide.md");
+  });
+
   it("keeps non-file relative links as normal markdown links", () => {
     const items: ConversationItem[] = [
       {
@@ -288,6 +313,33 @@ describe("Messages", () => {
     expect(openFileLinkMock).not.toHaveBeenCalled();
   });
 
+  it("keeps dot-relative non-file links as normal markdown links", () => {
+    const items: ConversationItem[] = [
+      {
+        id: "msg-help-dot-relative-href-link",
+        kind: "message",
+        role: "assistant",
+        text: "See [Help](./help/getting-started)",
+      },
+    ];
+
+    render(
+      <Messages
+        items={items}
+        threadId="thread-1"
+        workspaceId="ws-1"
+        isThinking={false}
+        openTargets={[]}
+        selectedOpenAppId=""
+      />,
+    );
+
+    const helpLink = screen.getByText("Help").closest("a");
+    expect(helpLink?.getAttribute("href")).toBe("./help/getting-started");
+    fireEvent.click(screen.getByText("Help"));
+    expect(openFileLinkMock).not.toHaveBeenCalled();
+  });
+
   it("does not crash or navigate on malformed codex-file links", () => {
     const items: ConversationItem[] = [
       {