Refactor chat file-link opens to a single disposition seam (#1038)

* Open chat file links in a side pane on cmd-click

* Add hover tooltips to file links showing cmd-click hint

* Collapse file-link open path to a single disposition seam

Replace the parallel "open in side" callback that was threaded
alongside the normal open callback at every layer between the chat
click handler and the workspace router. One callback now carries a
`OpenFileDisposition` ("main" | "side") so the modifier-key decision
lives at the leaf and the routing decision lives at the workspace
screen, with no branching in between.

* Give assistant file links a home

packages/app/src/components/message.tsx

@@ -68,7 +68,8 @@ import type { AgentAttachment } from "@server/shared/messages";
 import type { ToolCallDetail } from "@server/server/agent/agent-sdk-types";
 import { buildToolCallPresentation } from "@/tool-calls/presentation";
 import { resolveToolCallIcon } from "@/utils/tool-call-icon";
-import { type InlinePathTarget, parseInlinePathToken } from "@/utils/inline-path";
+import { parseInlinePathToken, type InlinePathTarget } from "@/utils/inline-path";
+import type { OpenFileDisposition } from "@/utils/workspace-file-open";
 import { getMarkdownListMarker, getMarkdownNextSiblingType } from "@/utils/markdown-list";
 import { type AssistantFileLinkSource } from "@/utils/assistant-file-link-resolver";
 import { useAssistantFileLinkResolver } from "@/hooks/use-assistant-file-link-resolver";
@@ -91,6 +92,11 @@ import {
 import { PlanCard } from "./plan-card";
 import { useToolCallSheet } from "./tool-call-sheet";
 import { ToolCallDetailsContent } from "./tool-call-details";
+import {
+  AssistantInlineCodePathLink,
+  AssistantMarkdownCodeLink,
+  AssistantMarkdownLink,
+} from "./assistant-file-link";
 import { getCompactionMarkerLabel } from "./message-compaction-label";
 import { useAttachmentPreviewUrl } from "@/attachments/use-attachment-preview-url";
 import { persistAttachmentFromBytes, persistAttachmentFromDataUrl } from "@/attachments/service";
@@ -709,7 +715,7 @@ export const LiveElapsed = memo(function LiveElapsed({
 interface AssistantMessageProps {
   message: string;
   timestamp: number;
-  onInlinePathPress?: (target: InlinePathTarget) => void;
+  onInlinePathPress?: (target: InlinePathTarget, disposition: OpenFileDisposition) => void;
   workspaceRoot?: string;
   serverId?: string;
   client?: DaemonClient | null;
@@ -1001,70 +1007,6 @@ function resolveAssistantImageErrorText(fileError: unknown, dataError: unknown):
   return "Unable to load image preview.";
 }
 
-function MarkdownLink({
-  source,
-  style,
-  onPress,
-  onPrefetch,
-  children,
-}: {
-  source: AssistantFileLinkSource;
-  style: StyleProp<TextStyle>;
-  onPress: (source: AssistantFileLinkSource) => void;
-  onPrefetch: (source: AssistantFileLinkSource) => void;
-  children: ReactNode;
-}) {
-  const [hovered, setHovered] = useState(false);
-  const href = source.href;
-  const handlePress = useCallback(() => onPress(source), [onPress, source]);
-  const handlePrefetch = useCallback(() => onPrefetch(source), [onPrefetch, source]);
-  const handleHoverIn = useCallback(() => {
-    setHovered(true);
-    handlePrefetch();
-  }, [handlePrefetch]);
-  const handleHoverOut = useCallback(() => setHovered(false), []);
-  const hoveredTextStyle = useMemo<StyleProp<TextStyle>>(
-    () => [style, hovered && { textDecorationLine: "underline" as const }],
-    [style, hovered],
-  );
-  if (isNative) {
-    return (
-      <Text accessibilityRole="link" onPress={handlePress} style={style}>
-        {children}
-      </Text>
-    );
-  }
-
-  return (
-    <a
-      href={href}
-      onClickCapture={preventAnchorNavigation}
-      onAuxClickCapture={preventAnchorNavigation}
-      style={MARKDOWN_LINK_ANCHOR_STYLE}
-    >
-      <Pressable
-        accessibilityRole="link"
-        onPress={handlePress}
-        onFocus={handlePrefetch}
-        onHoverIn={handleHoverIn}
-        onHoverOut={handleHoverOut}
-      >
-        <Text style={hoveredTextStyle}>{children}</Text>
-      </Pressable>
-    </a>
-  );
-}
-
-const MARKDOWN_LINK_ANCHOR_STYLE: React.CSSProperties = {
-  display: "contents",
-  color: "inherit",
-  textDecoration: "none",
-};
-
-function preventAnchorNavigation(event: React.MouseEvent<HTMLAnchorElement>): void {
-  event.preventDefault();
-}
-
 function getInlineCodeAutoLinkUrl(
   markdownParser: ReturnType<typeof MarkdownIt>,
   content: string,
@@ -1556,76 +1498,6 @@ function MarkdownInheritedText({
   return <Text style={style}>{children}</Text>;
 }
 
-interface MarkdownInheritedCodeLinkProps {
-  source: AssistantFileLinkSource;
-  inheritedStyles: TextStyle;
-  codeInlineStyle: TextStyle;
-  linkStyle: TextStyle;
-  onPress: (source: AssistantFileLinkSource) => void;
-  onPrefetch: (source: AssistantFileLinkSource) => void;
-  children: ReactNode;
-}
-
-function MarkdownInheritedCodeLink({
-  source,
-  inheritedStyles,
-  codeInlineStyle,
-  linkStyle,
-  onPress,
-  onPrefetch,
-  children,
-}: MarkdownInheritedCodeLinkProps) {
-  const style = useMemo(
-    () => [inheritedStyles, codeInlineStyle, linkStyle],
-    [inheritedStyles, codeInlineStyle, linkStyle],
-  );
-  return (
-    <MarkdownLink source={source} style={style} onPress={onPress} onPrefetch={onPrefetch}>
-      {children}
-    </MarkdownLink>
-  );
-}
-
-interface MarkdownInlinePathCodeLinkProps {
-  content: string;
-  inheritedStyles: TextStyle;
-  codeInlineStyle: TextStyle;
-  linkStyle: TextStyle;
-  onPress: (source: AssistantFileLinkSource) => void;
-  onPrefetch: (source: AssistantFileLinkSource) => void;
-}
-
-function MarkdownInlinePathCodeLink({
-  content,
-  inheritedStyles,
-  codeInlineStyle,
-  linkStyle,
-  onPress,
-  onPrefetch,
-}: MarkdownInlinePathCodeLinkProps) {
-  const source = useMemo<AssistantFileLinkSource>(
-    () => ({
-      href: content,
-      text: content,
-      sourceType: "inline-code",
-    }),
-    [content],
-  );
-
-  return (
-    <MarkdownInheritedCodeLink
-      source={source}
-      inheritedStyles={inheritedStyles}
-      codeInlineStyle={codeInlineStyle}
-      linkStyle={linkStyle}
-      onPress={onPress}
-      onPrefetch={onPrefetch}
-    >
-      {content}
-    </MarkdownInheritedCodeLink>
-  );
-}
-
 interface MarkdownListItemContentProps {
   contentStyle: ViewStyle;
   children: ReactNode;
@@ -1718,8 +1590,8 @@ export const AssistantMessage = memo(function AssistantMessage({
   });
 
   const handleLinkPress = useCallback(
-    (source: AssistantFileLinkSource) => {
-      fileLinkResolver.open({ source });
+    (source: AssistantFileLinkSource, disposition: OpenFileDisposition) => {
+      fileLinkResolver.open({ source, disposition });
     },
     [fileLinkResolver],
   );
@@ -1731,7 +1603,7 @@ export const AssistantMessage = memo(function AssistantMessage({
   );
   const handleMarkdownLinkPress = useCallback(
     (url: string) => {
-      fileLinkResolver.open({ source: { href: url } });
+      fileLinkResolver.open({ source: { href: url }, disposition: "main" });
       // react-native-markdown-display opens the link itself when this returns true.
       // We already handled it above, so return false to avoid duplicate opens.
       return false;
@@ -1815,7 +1687,7 @@ export const AssistantMessage = memo(function AssistantMessage({
 
         if (shouldResolveInlinePath) {
           return (
-            <MarkdownInlinePathCodeLink
+            <AssistantInlineCodePathLink
               key={node.key}
               content={content}
               inheritedStyles={inheritedStyles}
@@ -1823,6 +1695,7 @@ export const AssistantMessage = memo(function AssistantMessage({
               linkStyle={styles.link}
               onPress={handleLinkPress}
               onPrefetch={handleLinkPrefetch}
+              workspaceRoot={workspaceRoot}
             />
           );
         }
@@ -1834,7 +1707,7 @@ export const AssistantMessage = memo(function AssistantMessage({
             content,
           });
           return (
-            <MarkdownInheritedCodeLink
+            <AssistantMarkdownCodeLink
               key={node.key}
               source={source}
               inheritedStyles={inheritedStyles}
@@ -1842,9 +1715,10 @@ export const AssistantMessage = memo(function AssistantMessage({
               linkStyle={styles.link}
               onPress={handleLinkPress}
               onPrefetch={handleLinkPrefetch}
+              workspaceRoot={workspaceRoot}
             >
               {content}
-            </MarkdownInheritedCodeLink>
+            </AssistantMarkdownCodeLink>
           );
         }
 
@@ -1916,12 +1790,13 @@ export const AssistantMessage = memo(function AssistantMessage({
         </MarkdownParagraphView>
       ),
       link: (node: ASTNode, children: ReactNode[], _parent: ASTNode[], styles: MarkdownStyles) => (
-        <MarkdownLink
+        <AssistantMarkdownLink
           key={node.key}
           source={getMarkdownLinkSource(node)}
           style={styles.link}
           onPress={handleLinkPress}
           onPrefetch={handleLinkPrefetch}
+          workspaceRoot={workspaceRoot}
         >
           {Children.map(children, (child) => {
             if (!isValidElement(child)) return child;
@@ -1930,7 +1805,7 @@ export const AssistantMessage = memo(function AssistantMessage({
               style: [childProps.style, { color: styles.link.color }],
             } as Partial<{ style: StyleProp<TextStyle> }>);
           })}
-        </MarkdownLink>
+        </AssistantMarkdownLink>
       ),
       image: (
         node: ASTNode,