fix(session-ui): file-reference linkification is core, not a layout preference (#1839)

packages/app-bundle/manifest.json

@@ -487,12 +487,12 @@
     "packages/session-ui/src/components/build-trace.ts": "153e3182c3a37e4aca9c88bf0e2052b0ff4ec117a60d74d2c81567ab91180066",
     "packages/session-ui/src/components/group-parts.test.ts": "a31ce19009e1d62e75e83b682190a4613da0eed334420409ed73a9e21834ae84",
     "packages/session-ui/src/components/line-comment-styles.ts": "2077836c13bd3c3f1c39c67722119e448a2dfa123377f94bfd3676634e955d00",
-    "packages/session-ui/src/components/markdown-file-refs.test.ts": "e2b1bed33629d3ab53c521f33266814088ea4122b6e64d6ab294eacc4cf15070",
+    "packages/session-ui/src/components/markdown-file-refs.test.ts": "fc8e793bceb8ffad84baf1bcf3901863c7c770ca199fbe518fd1a8a9af5ced2a",
     "packages/session-ui/src/components/markdown-file-refs.ts": "b75bddeb565dc0163635fab8f84bdd26723742f9f82d06b6fd5991777b311032",
     "packages/session-ui/src/components/markdown-stream.test.ts": "b73b1a15ffa2cfea5358b2d6313ce17d26a5a11302b0e3b7d823cde0c98cbc83",
     "packages/session-ui/src/components/markdown-stream.ts": "50e38abd5d4ff919564655799678be10463dec58502fc5487c1c97a9a8db5399",
     "packages/session-ui/src/components/markdown.css": "24e7c19218620386647656a5d27e116cdeca911f1916c5d5b8609edca11ff165",
-    "packages/session-ui/src/components/markdown.tsx": "89e132e62d20c873311c9781d0ca4d7cd1a7ff882d99f19c8696aafaf4a8f298",
+    "packages/session-ui/src/components/markdown.tsx": "7a63e8eea8c0e6205ce4bb579de870fc05e1234ab2c7d49ac9b4a7ea1bd36285",
     "packages/session-ui/src/components/message-part-css.test.ts": "ffab7d2c94e8d40ca35e4a8d4383cc6efd805b133764176b70046fba874a5f06",
     "packages/session-ui/src/components/message-part-groups.ts": "37be069bf46e926fcde83d3744ee706911ff002e6b532e279290d841aeee96da",
     "packages/session-ui/src/components/message-part-skill.test.ts": "453bdcb25e4df91ad1004635b8766070a60421355adf18ee53f43cd2fa7d0486",
@@ -1010,7 +1010,7 @@
     "packages/ui/src/v2/components/text-shimmer-v2.tsx"
   ],
   "exceptions": [],
-  "extracted_at": "2026-10-21T17:55:52.656Z",
+  "extracted_at": "2026-10-22T10:48:47.701Z",
   "per_package": {
     "packages/app": {
       "A": 254,

packages/app-bundle/overlay/packages/session-ui/src/components/markdown-file-refs.test.ts

@@ -1,4 +1,6 @@
 import { beforeEach, describe, expect, test } from "bun:test"
+import { readFileSync } from "node:fs"
+import { resolve } from "node:path"
 import {
   cachedFileRef,
   clearFileRefCache,
@@ -66,3 +68,27 @@ describe("fileRefUrl", () => {
     expect(fileRefUrl("/Users/aaron/My Notes/insight-1.md")).toBe("file:///Users/aaron/My%20Notes/insight-1.md")
   })
 })
+
+// #1839 — file-reference linkification is a core capability, not a layout
+// preference. Reported live 2026-10-22: with data-new-layout off, every file
+// path in chat rendered as an inert pill — markInlineCode (the path-kind
+// tagging) and markFileLinks (the anchor wrapping) were both gated on the
+// new-layout body attribute, silently, with zero errors. The wiring must be
+// unconditional, like markExternalLinks (issue #270's precedent). Asserted on
+// the component source per the repo's component-source-assertion convention.
+describe("file-ref wiring is not layout-gated (#1839)", () => {
+  const source = readFileSync(resolve(__dirname, "markdown.tsx"), "utf8")
+
+  test("decorate tags inline-code pills unconditionally — no new-layout early return", () => {
+    const start = source.indexOf("function decorate(")
+    const body = source.slice(start, source.indexOf("function markExternalLinks("))
+    expect(start).toBeGreaterThan(0)
+    expect(body).toContain("markInlineCode(root)")
+    expect(body).not.toContain("data-new-layout")
+  })
+
+  test("markFileLinks runs unconditionally in the render effect", () => {
+    expect(source).toContain("markFileLinks(container)")
+    expect(source).not.toContain('data-new-layout")) markFileLinks')
+  })
+})

packages/app-bundle/overlay/packages/session-ui/src/components/markdown.tsx

@@ -339,7 +339,9 @@ function decorate(root: HTMLDivElement, labels: CopyLabels) {
   // This must run unconditionally, not just in new-layout mode
   markExternalLinks(root)
   markCodeLinks(root)
-  if (!document.body.hasAttribute("data-new-layout")) return
+  // #1839: the inline-code pill tagging is the data layer for file-reference
+  // linkification (markFileLinks consumes data-inline-code-kind) — a core
+  // capability, not a layout preference. Runs unconditionally.
   markInlineCode(root)
 }
 
@@ -595,9 +597,12 @@ export function Markdown(
         copied: i18n.t("ui.message.copied"),
       }))
     if (!linkCleanup) linkCleanup = setupExternalLinks(container)
-    // File-reference linkification rides the same new-layout gate as the
-    // inline-code pill tagging (decorate) whose data attributes it consumes.
-    if (document.body.hasAttribute("data-new-layout")) markFileLinks(container)
+    if (!linkCleanup) linkCleanup = setupExternalLinks(container)
+    // #1839: file-reference linkification is core, not a layout preference —
+    // runs unconditionally (the pills it consumes are tagged unconditionally
+    // in decorate). The live report: with data-new-layout off, every file
+    // link in chat was silently inert.
+    markFileLinks(container)
   })
 
   onCleanup(() => {