diff --git a/.github/workflows/sanity.yml b/.github/workflows/sanity.yml
index 847d0cb..8894fca 100644
--- a/.github/workflows/sanity.yml
+++ b/.github/workflows/sanity.yml
@@ -15,14 +15,14 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
 
       - name: Check public-preview file set
         shell: bash
         run: |
           set -euo pipefail
 
-          for file in AGENTS.md CLAUDE.md CHANGELOG.md CONTRIBUTING.md LICENSE README.md SECURITY.md manifest.json package.json docs/00_goal.md docs/01_requirements.md docs/02_runbook.md docs/03_status.md docs/04_decisions.md docs/06_mv3_design.md docs/07_manual_verification.md docs/08_manual_verification_result_template.md
+          for file in .github/dependabot.yml AGENTS.md CLAUDE.md CHANGELOG.md CONTRIBUTING.md LICENSE README.md SECURITY.md manifest.json package.json docs/00_goal.md docs/01_requirements.md docs/02_runbook.md docs/03_status.md docs/04_decisions.md docs/06_mv3_design.md docs/07_manual_verification.md docs/08_manual_verification_result_template.md
           do
             test -f "$file"
           done
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 00b1d85..50c48aa 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -11,6 +11,13 @@ All notable product changes will be recorded in this file.
 - Added unsupported-page safeguards and exact manifest-permission tests.
 - Added immediate `Copied!` feedback with timed label restoration.
 - Added public-safe manual verification guidance.
+- Restricted body and comment extraction to visible `innerText` without hidden
+  `textContent` fallback.
+- Added page title provenance to Markdown output.
+- Added structural blockquote boundaries for untrusted body and comment
+  previews.
+- Added regression checks for hidden content, Markdown structure, background
+  runtime absence, and external communication primitives.
 
 This entry describes the source preview. It is not a release, tag, package, or
 Chrome Web Store publication record.
diff --git a/README.md b/README.md
index 8647ddd..b368f44 100644
--- a/README.md
+++ b/README.md
@@ -17,7 +17,8 @@ a complete GitHub conversation exporter.
 - recognizes GitHub Issue pages
 - recognizes GitHub Pull Request conversation pages
 - extracts the visible title, source URL, body preview, and visible comment snippets
-- creates a Markdown preview with explicit limitations and a review-before-sharing warning
+- creates a Markdown preview with the title, explicit limitations, and a review-before-sharing warning
+- keeps body and comment previews inside an explicit untrusted-content blockquote boundary
 - copies the Markdown to the clipboard
 - saves the Markdown as a local `.md` file
 - fails closed when metadata injection fails
@@ -70,7 +71,8 @@ See [SECURITY.md](SECURITY.md) for the security policy and reporting route.
 defines reusable maintainer handoff and task-packet structures. GitHub Web
 Context Exporter is a smaller browser-side entry point that captures only the
 currently visible GitHub page context. It does not replace repository-aware
-context gathering or generate a complete task packet.
+context gathering or generate a complete task packet. The projects do not
+automatically transfer files or share a runtime schema.
 
 ## Development
 
diff --git a/SECURITY.md b/SECURITY.md
index 72ddae2..11bfc8c 100644
--- a/SECURITY.md
+++ b/SECURITY.md
@@ -11,8 +11,8 @@ made for earlier preview revisions.
 
 ## Report a vulnerability
 
-After the public repository enables GitHub Private Vulnerability Reporting,
-use the repository's **Security** tab and select **Report a vulnerability**.
+Use GitHub Private Vulnerability Reporting from the repository's **Security**
+tab and select **Report a vulnerability**.
 
 Do not place credentials, private repository content, private logs, identifying
 screenshots, or exploit details in a public Issue. If the private reporting
diff --git a/docs/01_requirements.md b/docs/01_requirements.md
index 6b5cce3..c0884a4 100644
--- a/docs/01_requirements.md
+++ b/docs/01_requirements.md
@@ -32,6 +32,7 @@ Pull Request support is limited to the Conversation page.
 - page title
 - visible body preview or an explicit unavailable fallback
 - visible comment snippets or an explicit unavailable fallback
+- body and comment previews structurally marked as untrusted page content
 
 The preview does not claim complete state, label, body, comment, review,
 diff, check, or files-changed coverage.
@@ -66,3 +67,4 @@ diff, check, or files-changed coverage.
 - no analytics or cloud sync
 - no GitHub write operation
 - manual review required before sharing exported Markdown
+- no automatic transfer to Maintainer Context Kit
diff --git a/docs/02_runbook.md b/docs/02_runbook.md
index 698bd5d..b1de03c 100644
--- a/docs/02_runbook.md
+++ b/docs/02_runbook.md
@@ -16,7 +16,8 @@ npm test
 
 The suite covers URL classification, Markdown formatting, filename generation,
 manifest permissions, self-contained metadata injection, fail-closed behavior,
-unsupported pages, and Copy feedback.
+hidden-content exclusion, untrusted Markdown framing, runtime network
+boundaries, unsupported pages, and Copy feedback.
 
 ## Load unpacked
 
diff --git a/docs/03_status.md b/docs/03_status.md
index 055dda4..b346b5f 100644
--- a/docs/03_status.md
+++ b/docs/03_status.md
@@ -1,10 +1,10 @@
 # Status
 
-Last updated: 2026-07-16
+Last updated: 2026-07-30
 
 ## Current phase
 
-Maintainer-controlled OSS preview candidate.
+Maintainer-controlled public OSS preview.
 
 ## Implemented
 
@@ -12,9 +12,13 @@ Maintainer-controlled OSS preview candidate.
 - GitHub Issue and Pull Request Conversation URL classification
 - self-contained visible-page metadata injection
 - visible title, source URL, body preview, and visible comment snippets
-- explicit selector fallbacks
+- rendered-visibility checks that reject hidden, inert, transparent, or
+  non-rendered body/comment elements
+- explicit body selectors that do not promote the first comment into a
+  missing body preview
 - fail-closed injection-error behavior
 - Markdown preview with limitation and review-before-sharing sections
+- title provenance and blockquoted untrusted body/comment previews
 - Copy Markdown with immediate `Copied!` feedback and timed restoration
 - local Markdown save without the Chrome Downloads API
 - exact manifest-permission regression tests
@@ -48,11 +52,30 @@ There are no host permissions.
 
 ## Verification baseline
 
-- automated test suite: 29 tests
-- public-safe Issue and Pull Request Conversation checks
-- unsupported repository-root check
-- Copy and Download checks
-- manifest-permission check
+- automated test suite: 38 tests in this local candidate
+- exact local candidate loaded with `Load unpacked` in an isolated Chrome for
+  Testing profile on 2026-07-30
+- public-safe Issue check covering title, canonical URL, visible body, and
+  visible comments
+- public-safe Pull Request Conversation check covering title, canonical URL,
+  visible body, and an explicit no-visible-comments fallback
+- unsupported repository-root check with no Markdown and disabled Copy/save
+- successful user-gesture Copy check, including `Copied!` feedback and timed
+  restoration
+- successful local Markdown save for both the Issue and Pull Request
+- manifest-permission check for `activeTab`, `scripting`, and `clipboardWrite`,
+  with no host permissions
 
 Verification results describe the tested revision only and are not a
 production-readiness guarantee.
+
+## Current product interpretation
+
+The extension is a short orientation snapshot, not a faithful full-conversation
+export. Body and comment previews are deliberately capped. State, labels,
+complete bodies, full comment history, review threads, diffs, and check results
+remain outside the current scope.
+
+Maintainer Context Kit is a separate repository-aware workflow. There is no
+automatic file import, stdin bridge, or shared runtime schema between the
+projects.
diff --git a/docs/04_decisions.md b/docs/04_decisions.md
index cb76c98..c2142e1 100644
--- a/docs/04_decisions.md
+++ b/docs/04_decisions.md
@@ -58,3 +58,12 @@ export, redaction, or secret-scanner claims.
 
 Reason: the tested local workflow is useful, while broader distribution and
 support promises remain out of scope.
+
+## Independent cross-product operation
+
+Decision: keep this extension and Maintainer Context Kit independently
+operable. Do not add file import, stdin transfer, or a shared runtime schema
+without repeated workflow evidence that manual transfer is a material problem.
+
+Reason: the products have different trust and collection boundaries. Coupling
+them now would add maintenance surface without demonstrated user demand.
diff --git a/docs/06_mv3_design.md b/docs/06_mv3_design.md
index 2f3fd22..4fd9d8c 100644
--- a/docs/06_mv3_design.md
+++ b/docs/06_mv3_design.md
@@ -27,6 +27,8 @@ The extension has no service worker or content-script registration.
 6. The popup validates the injection result and fails closed if extraction did
    not execute successfully.
 7. The formatter creates a visible-page-only Markdown preview.
+   Page-derived body and comment previews remain inside blockquotes marked as
+   untrusted content.
 8. The user can copy or locally save the Markdown.
 
 ## Supported URL patterns
@@ -42,6 +44,9 @@ Prefer an explicit fallback or extraction failure over a misleading export.
 Hidden, collapsed, paginated, dynamically unloaded, diff, check, and
 files-changed content is outside the completeness claim.
 
+The extractor uses visible `innerText` for page-derived body and comment
+content. It does not fall back to hidden `textContent`.
+
 ## Rendering principle
 
 Page-derived content is rendered through `textContent` or form-control
diff --git a/docs/07_manual_verification.md b/docs/07_manual_verification.md
index d358d73..56a5dfa 100644
--- a/docs/07_manual_verification.md
+++ b/docs/07_manual_verification.md
@@ -1,6 +1,6 @@
 # Manual Verification Guide
 
-Last updated: 2026-07-16
+Last updated: 2026-07-30
 
 This guide verifies the current local extension behavior. It is not a release or store-publishing checklist.
 
@@ -48,17 +48,19 @@ If testing on private repository pages, do not paste, publish, screenshot, or sh
 4. Confirm the Markdown preview includes:
    - `GitHub Issue Context`
    - `Source`
+   - the current document title and page URL under `Source`
    - `Limitations`
    - `Review Before Sharing`
    - `Body Preview`
    - `Visible Comments Preview`
    - `Suggested Next Use`
-5. Click `Copy Markdown`.
-6. Confirm the button immediately changes to `Copied!`.
-7. Confirm the button returns to `Copy Markdown` after about 1.5 seconds.
-8. Paste into a local scratch document and confirm Markdown was copied.
-9. Click `Download Markdown`.
-10. Confirm a local `.md` file is saved with a repository/page-based filename.
+5. Confirm body and comment snippets are blockquoted as untrusted page content.
+6. Click `Copy Markdown`.
+7. Confirm the button immediately changes to `Copied!`.
+8. Confirm the button returns to `Copy Markdown` after about 1.5 seconds.
+9. Paste into a local scratch document and confirm Markdown was copied.
+10. Click `Download Markdown`.
+11. Confirm a local `.md` file is saved with a repository/page-based filename.
 
 ## Verify a Pull Request conversation page
 
@@ -74,13 +76,15 @@ If testing on private repository pages, do not paste, publish, screenshot, or sh
 4. Confirm the Markdown preview includes:
    - `GitHub Pull Request Context`
    - `Source`
+   - the current document title and page URL under `Source`
    - `Limitations`
    - `Review Before Sharing`
    - `Body Preview`
    - `Visible Comments Preview`
    - `Suggested Next Use`
-5. Confirm the preview does not claim to include Files changed, diffs, checks, hidden content, or complete review threads.
-6. Confirm Copy and Download behave the same as on Issue pages.
+5. Confirm body and comment snippets are blockquoted as untrusted page content.
+6. Confirm the preview does not claim to include Files changed, diffs, checks, hidden or collapsed content, or complete review threads.
+7. Confirm Copy and Download behave the same as on Issue pages.
 
 ## Verify unsupported pages
 
@@ -116,6 +120,10 @@ Manual verification passes when:
 
 - supported Issue pages produce a Markdown preview
 - supported Pull Request conversation pages produce a Markdown preview
+- Source records the current document title and page URL
+- body and comment snippets remain inside blockquotes as untrusted content
+- hidden or collapsed DOM content is not promoted into body or comment previews
+- a visible comment is not promoted into a missing body preview
 - unsupported pages fail safely
 - Copy Markdown works, shows `Copied!`, and restores its label
 - Download Markdown saves a local `.md` file
@@ -131,4 +139,6 @@ Stop and open a follow-up issue if:
 - the output claims completeness that is not implemented
 - permissions expand unexpectedly
 - generated Markdown omits the review-before-sharing warning
+- hidden or collapsed DOM text appears in the generated preview
+- a comment is mislabeled as the page body
 - local save requires a new permission
diff --git a/docs/08_manual_verification_result_template.md b/docs/08_manual_verification_result_template.md
index 348a326..e4de725 100644
--- a/docs/08_manual_verification_result_template.md
+++ b/docs/08_manual_verification_result_template.md
@@ -21,7 +21,7 @@ Do not expand extraction scope until this result is filled out and any blocking
 
 Choose one:
 
-- [ ] Pass: current behavior is acceptable for continued private iteration.
+- [ ] Pass: current behavior is acceptable for the maintainer-controlled public preview.
 - [ ] Conditional pass: minor issues recorded below; no privacy, permission, or misleading-output blocker.
 - [ ] Fail: stop feature expansion and fix blockers first.
 
@@ -45,8 +45,12 @@ Notes:
 - [ ] Type is `issue`.
 - [ ] Number is shown.
 - [ ] Page title is shown or clear fallback appears.
+- [ ] Source includes the current document title and page URL.
 - [ ] Body Preview appears or clear fallback appears.
 - [ ] Visible Comments Preview appears or clear fallback appears.
+- [ ] Body and comment snippets are blockquoted as untrusted content.
+- [ ] Hidden or collapsed content is not included.
+- [ ] A visible comment is not mislabeled as a missing body.
 - [ ] Markdown preview includes limitation language.
 - [ ] Markdown preview includes review-before-sharing language.
 
@@ -62,8 +66,12 @@ Notes:
 - [ ] Type is `pull request`.
 - [ ] Number is shown.
 - [ ] Page title is shown or clear fallback appears.
+- [ ] Source includes the current document title and page URL.
 - [ ] Body Preview appears or clear fallback appears.
 - [ ] Visible Comments Preview appears or clear fallback appears.
+- [ ] Body and comment snippets are blockquoted as untrusted content.
+- [ ] Hidden or collapsed content is not included.
+- [ ] A visible comment is not mislabeled as a missing body.
 - [ ] Markdown preview does not claim Files changed, diffs, checks, or complete review threads.
 
 Notes:
@@ -150,7 +158,7 @@ List issues that may be fixed later.
 
 Choose one:
 
-- [ ] Continue private iteration.
+- [ ] Continue the maintainer-controlled public preview.
 - [ ] Fix blockers before further development.
 - [ ] Re-run manual verification after fixes.
 
diff --git a/test/runtimeBoundary.test.mjs b/test/runtimeBoundary.test.mjs
new file mode 100644
index 0000000..001da2a
--- /dev/null
+++ b/test/runtimeBoundary.test.mjs
@@ -0,0 +1,52 @@
+import test from "node:test";
+import assert from "node:assert/strict";
+import { readdir, readFile } from "node:fs/promises";
+import { extname } from "node:path";
+
+async function runtimeSource() {
+  const root = new URL("../src/", import.meta.url);
+  const pending = [root];
+  const files = [];
+
+  while (pending.length > 0) {
+    const directory = pending.pop();
+    const entries = await readdir(directory, { withFileTypes: true });
+
+    for (const entry of entries) {
+      const url = new URL(entry.name, directory);
+      if (entry.isDirectory()) {
+        url.pathname += "/";
+        pending.push(url);
+      } else if (extname(entry.name) === ".js") {
+        files.push(await readFile(url, "utf8"));
+      }
+    }
+  }
+
+  return files.join("\n");
+}
+
+test("manifest keeps the no-background and no-remote-code boundary", async () => {
+  const manifest = JSON.parse(await readFile(new URL("../manifest.json", import.meta.url), "utf8"));
+
+  assert.equal(manifest.background, undefined);
+  assert.equal(manifest.content_scripts, undefined);
+  assert.equal(manifest.externally_connectable, undefined);
+  assert.equal(manifest.update_url, undefined);
+});
+
+test("runtime source contains no external communication primitives", async () => {
+  const source = await runtimeSource();
+  const forbidden = [
+    /\bfetch\s*\(/,
+    /\bXMLHttpRequest\b/,
+    /\bWebSocket\b/,
+    /\bEventSource\b/,
+    /\bsendBeacon\s*\(/,
+    /\bconnectNative\s*\(/
+  ];
+
+  for (const pattern of forbidden) {
+    assert.equal(pattern.test(source), false, `${pattern} must not appear in runtime source`);
+  }
+});