phase: 138_markdown_blockquotes

**Phase 138 final verification pass — all green, no defects found.**

- Verified: blockquote pass in `frontend/assets/markdown.js` (step 2b, between escape+inline and paragraphs), guard extended to `|blockquote`, docstring updated; `.md-quote` CSS (left border + padding + `--ink-soft`, no fill, palette vars only, contrast comments, user-bubble override); unit pins + node behavior; dedicated E2E (chat / viewer / restore); mock `QUOTE_TRIGGER`/`QUOTE_ANSWER`; fixture `tests/fixtures/quote_docs/`. Thinking block confirmed on the same shared renderer (app.js L2025/L3095).
- `uv run pytest tests/e2e/test_markdown_blockquotes.py -v --no-cov` → 3 passed (isolation)
- `uv run pytest --cov=app --cov-report=term-missing` → 3268 passed, 9 skipped; TOTAL **99%** (>90%)
- `uv run ruff check . && uv run pyright` → All checks passed; 0 errors
- Criteria: quotes render in chat/viewer/restore ✅ (E2E) + thinking ✅ (shared renderer + unscoped AA CSS); `>>` collapses, fence/table `>` untouched ✅ (unit+e2e); non-quote byte-identical ✅ (exact fixture; phase-44/renderer suites pass **unedited**, confirmed by empty `git diff --stat`)
- No deviations; commit + phase-dir move left to the harness per pipeline rules (working tree clean of stray changes — only phase-138 diffs present)
- Next pending phase: **139_read_range_tool_lines**

tests/unit/test_markdown_blockquotes.py

@@ -0,0 +1,271 @@
+"""Unit: the shared renderer's markdown blockquote pass (phase 138, task 01).
+
+Browser behavior is E2E-covered by ``tests/e2e/test_markdown_blockquotes.py``
+(task 03); here we pin the source-level contract — the pass ordering
+(fences → tables → escape+inline → blockquotes → paragraphs → restore),
+the group rule (maximal run of ``>``-prefixed lines; blank line
+terminates; nested collapses — locked A1), the exact output marker, the
+extended paragraph guard, and the ``.md-quote`` CSS rule (palette vars
+only — task 02's pin) — so a silent regression is caught without a
+browser (the established frontend pattern). A small node-driven
+behavioral check (skipped when node is unavailable, like the phase-44
+table check) proves the story acceptance shapes: single-line quote,
+multi-line group, nested collapse, XSS quote inert, fence-wins,
+table-cell untouched, blank-line termination, and non-quote input
+byte-identical to the pre-phase renderer (fixture string checked into
+the test, per the phase-44 shape).
+"""
+from __future__ import annotations
+
+import json
+import re
+import shutil
+import subprocess
+from pathlib import Path
+
+import pytest
+
+FRONTEND = Path(__file__).resolve().parents[2] / "frontend"
+ASSETS = FRONTEND / "assets"
+MARKDOWN_JS = ASSETS / "markdown.js"
+STYLES_CSS = ASSETS / "styles.css"
+
+HAVE_NODE = shutil.which("node") is not None
+
+MARKER = '<blockquote class="md-quote">'
+
+#: The non-quote input (a paragraph + list + a pipe table) and its
+#: byte-EXACT pre-phase renderer output (the fixture string checked
+#: into the test, per the phase-44 shape) — the byte-identity contract
+#: (phase 138 design): anything without a quote line renders exactly
+#: as it did before the blockquote pass existed. (The blank line before
+#: the list is absorbed by the pre-existing ``^\\s*[-*] `` list rule —
+#: the fixture pins that too.)
+NO_QUOTE_INPUT = (
+    "A plain paragraph about the homelab.\n"
+    "\n"
+    "- item one\n"
+    "- item two\n"
+    "\n"
+    "| Col A | Col B |\n"
+    "|---|---|\n"
+    "| 1 | 2 |"
+)
+NO_QUOTE_PRE_PHASE_OUTPUT = (
+    "<p>A plain paragraph about the homelab.<br>"
+    "<ul><li>item one</li><br><li>item two</li></ul></p>"
+    '<p><div class="md-table-wrap">\n'
+    '<table class="md-table">\n'
+    '<thead><tr><th scope="col">Col A</th><th scope="col">Col B</th></tr></thead>\n'
+    "<tbody><tr><td>1</td><td>2</td></tr></tbody>\n"
+    "</table>\n</div></p>"
+)
+
+
+def _text(path: Path) -> str:
+    assert path.is_file(), f"missing frontend file: {path}"
+    return path.read_text(encoding="utf-8")
+
+
+def _run_node(script: str) -> str:
+    proc = subprocess.run(["node", "-e", script], capture_output=True, text=True, timeout=60)
+    assert proc.returncode == 0, f"node failed: {proc.stderr}"
+    return proc.stdout
+
+
+# ---------- markdown.js: the blockquote pass (step 2b) ----------
+
+
+def test_blockquote_pass_runs_after_inline_and_before_paragraphs() -> None:
+    """The pass order is fences → tables → escape+inline → blockquotes
+    → paragraphs → restore (phase 138 design). The blockquote pass sits
+    between step 2 (``inline(escapeHtml(text))`` — after it, a quote
+    line starts with the escaped ``&gt;`` marker) and step 3 (the
+    paragraph split), so inline code/strong/em already work inside
+    quotes for free and the paragraph guard leaves the block alone."""
+    js = _text(MARKDOWN_JS)
+    inline_step = "text = inline(escapeHtml(text));"
+    quote_pass = 'const quoteLines = text.split("\\n");'
+    para_split = "split(/\\n{2,}/)"
+    assert inline_step in js, "step 2 still escapes+inlines the whole text"
+    assert quote_pass in js, "the blockquote pass splits the text into lines"
+    assert js.find(inline_step) < js.find(quote_pass), (
+        "the blockquote pass must run AFTER the escape+inline step "
+        "(a quote line only starts with &gt; once escaped)"
+    )
+    assert js.find(quote_pass) < js.find(para_split), (
+        "the blockquote pass must run BEFORE the paragraph split"
+    )
+
+
+def test_paragraph_guard_includes_blockquote() -> None:
+    """The step-3 block-element guard extends to
+    ``/^<(h\\d|ul|ol|pre|li|blockquote)/`` so the paragraph pass leaves
+    the emitted <blockquote> alone (no <p> wrap) — the pre-phase guard
+    (without blockquote) must be gone."""
+    js = _text(MARKDOWN_JS)
+    assert r"/^<(h\d|ul|ol|pre|li|blockquote)/" in js, (
+        "the step-3 guard must include blockquote"
+    )
+    assert r"/^<(h\d|ul|ol|pre|li)/" not in js, (
+        "the pre-phase guard (without blockquote) must be replaced"
+    )
+
+
+def test_blockquote_marker_and_group_rule() -> None:
+    """The exact output marker string and the group rule: the maximal
+    run of consecutive lines matching ``^\\s*(?:&gt;)+ ?`` (leading
+    whitespace allowed, the nested ``>>``/``>>>`` run allowed, ONE
+    optional space after the run) is ONE
+    ``<blockquote class="md-quote">`` — the marker run + one optional
+    space is stripped from each member, members join with ``<br>``
+    (the paragraph convention)."""
+    js = _text(MARKDOWN_JS)
+    assert MARKER in js, "the exact marker string must be emitted"
+    group_rule = r"^\s*(?:&gt;)+ ?"
+    assert js.count(group_rule) >= 2, (
+        "the group rule ^\\s*(?:&gt;)+ ? must both TEST and STRIP "
+        "(one occurrence in the test, one in the strip replace)"
+    )
+    assert re.search(r'members\.join\("<br>"\)', js), (
+        "group members must be joined with <br>"
+    )
+    # the strip replaces the leading run (+ one optional space) — the
+    # nested >> collapses to one level (locked A1)
+    assert r'replace(/^\s*(?:&gt;)+ ?/, "")' in js, (
+        "the strip must remove the &gt; run plus ONE optional space"
+    )
+
+
+def test_md_quote_css_references_palette_vars_only() -> None:
+    """Task 02's pin: the ``.md-quote`` rule (and the user-bubble
+    override, if present) reference :root palette vars ONLY — no
+    hex/rgb/hsl color literal (the :root-drift unit test parses the
+    built-ins from this file, so a literal here would be a second
+    source of truth), and the rule block carries a >=4.5:1 contrast
+    note per the house comment convention."""
+    css = _text(STYLES_CSS)
+    root = re.search(r":root\s*\{", css)
+    assert root, "styles.css must define :root"
+    root_body = css[root.end() : css.find("}", root.end())]
+    palette = set(re.findall(r"(--[a-z0-9-]+)\s*:", root_body))
+    assert palette, "the :root palette must declare variables"
+
+    rule_bodies = re.findall(r"(?<![-\w])\.md-quote\s*\{([^}]*)\}", css)
+    assert rule_bodies, "styles.css must define .md-quote"
+    for body in rule_bodies:
+        refs = re.findall(r"var\((--[a-z0-9-]+)\)", body)
+        assert refs, ".md-quote must reference palette vars"
+        for ref in refs:
+            assert ref in palette, f"{ref} is not a :root palette var"
+        assert not re.search(r"#[0-9a-fA-F]{3,8}\b", body), (
+            "no hex color literal in .md-quote"
+        )
+        assert "rgb(" not in body and "hsl(" not in body, (
+            "no rgb()/hsl() color literal in .md-quote"
+        )
+
+    # the contrast note (house convention, cf. --ink-soft's
+    # "8.2:1 on --surface"): the comment block immediately above the
+    # rule carries a ratio
+    rule_pos = css.find(".md-quote {")
+    assert rule_pos != -1
+    comment_start = css.rfind("/*", 0, rule_pos)
+    comment_block = css[comment_start:rule_pos]
+    assert re.search(r"\d+(?:\.\d+)?\s*:\s*1", comment_block), (
+        "the .md-quote rule must carry a contrast-ratio note"
+    )
+
+
+# ---------- behavior (node): the story's acceptance shapes ----------
+
+
+@pytest.mark.skipif(not HAVE_NODE, reason="node not available")
+def test_blockquote_renders_semantic_xss_safe_and_precedence_holds() -> None:
+    """The story shapes executed under node: (1) a single-line quote
+    renders ONE <blockquote class="md-quote"> with no literal &gt;
+    (the bug, TODO.md L3); (2) a 3-line group is ONE blockquote with
+    <br> joins; (3) nested >> / >>> collapses to one level (locked A1);
+    (4) a blank line terminates the group (two blockquotes); (5) an
+    <script> in a quote is escaped — inert text, no live tag; (6) a >
+    inside a code fence stays fence content (step 1 protects first);
+    (7) a > in a table cell stays cell text (step 1b protects, step 4
+    restores after the pass); (8) a quote line still carries inline
+    code/strong/em (the inline chain ran first); (9) non-quote input
+    (paragraph + list + table) renders byte-identical to the
+    pre-phase renderer (the checked-in fixture string)."""
+    js = _text(MARKDOWN_JS)
+    cases: dict[str, tuple[str, list[str], list[str], str | None]] = {
+        # name: (input, must_contain, must_not, exact_output_or_None)
+        "single": (
+            "> quoted",
+            [],
+            [],
+            MARKER + "quoted</blockquote>",
+        ),
+        "group": (
+            "> a\n> b\n> c",
+            [],
+            [],
+            MARKER + "a<br>b<br>c</blockquote>",
+        ),
+        "nested": (
+            ">> nested\n>>> deeper",
+            [],
+            ["<blockquote class=\"md-quote\"><blockquote"],
+            MARKER + "nested<br>deeper</blockquote>",
+        ),
+        "blank_terminates": (
+            "> one\n\n> two",
+            [],
+            [],
+            MARKER + "one</blockquote>" + MARKER + "two</blockquote>",
+        ),
+        "xss": (
+            "> <script>alert(1)</script>",
+            [],
+            ["<script>"],
+            MARKER + "&lt;script&gt;alert(1)&lt;/script&gt;</blockquote>",
+        ),
+        "fence": (
+            "```\n> x\n```",
+            [],
+            ["<blockquote"],
+            "<p><pre><code>&gt; x</code></pre></p>",
+        ),
+        "cell": (
+            "| a |\n|---|\n| > x |",
+            ["<td>&gt; x</td>"],
+            ["<blockquote"],
+            None,
+        ),
+        "inline": (
+            "> **bold** and `code`",
+            [],
+            [],
+            MARKER + "<strong>bold</strong> and <code>code</code></blockquote>",
+        ),
+        "noquote": (
+            NO_QUOTE_INPUT,
+            [],
+            ["<blockquote"],
+            NO_QUOTE_PRE_PHASE_OUTPUT,
+        ),
+    }
+    driver = (
+        js
+        + "\nconst out = {}; "
+        + "".join(
+            f"out.{name} = renderMarkdown({value!r}); " for name, (value, _, _, _) in cases.items()
+        )
+        + "console.log(JSON.stringify(out));"
+    )
+    results = json.loads(_run_node(driver))
+    for name, (_, must_contain, must_not, exact) in cases.items():
+        html = results[name]
+        if exact is not None:
+            assert html == exact, f"{name}: {html!r} != pre-phase/contract shape {exact!r}"
+        for marker in must_contain:
+            assert marker in html, f"{name}: missing {marker!r} in {html!r}"
+        for marker in must_not:
+            assert marker not in html, f"{name}: unexpected {marker!r} in {html!r}"