diff --git a/CHANGELOG.md b/CHANGELOG.md
index 4ab00622..82f70a89 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,31 @@
 # Hermes Web UI -- Changelog
 
+## [v0.51.22] — 2026-05-07 — 3-PR batch (P0 markdown streaming hotfix + CSP source-map allowance + LaTeX delimiter rendering)
+
+### Fixed (3 PRs)
+
+- **PR #1851** by @ChaseFlorell — **P0 hotfix**: ES module import for `static/vendor/smd.min.js` used a bare specifier (`import * as smd from 'static/vendor/smd.min.js'`) which the [HTML spec](https://html.spec.whatwg.org/multipage/webappapis.html#resolve-a-module-specifier) rejects — relative ES module references must start with `/`, `./`, or `../`. Result: the entire `<script type="module">` block in `static/index.html` failed silently, `window.smd` was never set, and live token-by-token markdown streaming was broken for all users since the streaming-markdown library landed. Fix: change `'static/vendor/smd.min.js'` → `'/static/vendor/smd.min.js'`. 1-LOC change. Browser-verified post-fix: `typeof window.smd === 'object'` with all expected exports (BLOCKQUOTE, CODE_FENCE, EQUATION_BLOCK, etc.). Closes #1849.
+
+- **PR #1852** by @ChaseFlorell — CSP `connect-src 'self'` blocked DevTools-initiated fetches of source maps for the three xterm.js libraries (xterm@5.3.0, xterm-addon-fit@0.8.0, xterm-addon-web-links@0.9.0) loaded from `cdn.jsdelivr.net`. The script tags loaded fine (covered by `script-src https://cdn.jsdelivr.net`), but `.js.map` files are fetched via `connect` and got blocked, emitting CSP violation errors in the console whenever DevTools was open. Fix: add `https://cdn.jsdelivr.net` to `connect-src` in `api/helpers.py:_security_headers()`, alongside the existing `'self'`. Consistent with the existing jsDelivr allowlist on `script-src`/`style-src`/`font-src`. New regression test `test_issue1850_csp_connect_src_jsdelivr.py` pins both the new entry and that `'self'` is preserved. Closes #1850.
+
+- **PR #1848** by @Michaelyklam — Backslash LaTeX delimiters (`\[...\]` for display, `\(...\)` for inline) didn't render through the KaTeX pipeline. The renderer already supported `$$...$$` / `$...$`, but the prior regex for `\\(...\\)` / `\\[...\\]` required a *double* backslash, which is the JavaScript-source escape form, not the form LLMs actually emit in chat content. Result: multi-line display math from real assistant output appeared as raw `\[ ... \]` text with `<br>` line breaks instead of a centered KaTeX block. Fix in `static/ui.js`: math-stash regex relaxed to single backslashes, and the user-bubble path (`_renderUserFencedBlocks`) gets its own pre-escape math stash so backslash delimiters survive `esc()` instead of being HTML-escaped to `&#92;`. Test `test_backslash_latex_delimiters_render_to_katex_placeholders` runs the assistant and user pipelines via Node and asserts no raw delimiter leakage in either rendered output. Closes #1847.
+
+### Maintainer-side absorption
+
+- **`tests/test_streaming_markdown.py` + `tests/test_subpath_frontend_routes.py`** — tightened the smd-import-shape assertions to require the `./` relative form and forbid BOTH bare specifier (broken by ES spec, #1849) AND root-absolute (breaks `/hermes/` subpath mounts). The original tests only forbade root-absolute, which let the bare-specifier regression land unnoticed in the first place. PR #1851's original fix used the root-absolute form (which would have re-broken subpath deployments); the corrected `./` form satisfies both constraints. Subpath safety verified: `new URL('./static/vendor/smd.min.js', 'http://host/hermes/').href === 'http://host/hermes/static/vendor/smd.min.js'`.
+
+### Tests
+
+4810 → **4815 collected** (+5). Three new from #1848 augmenting `test_issue347.py` (Node-driven `_run_renderers()` harness for assistant + user pipelines), two new in `test_issue1850_csp_connect_src_jsdelivr.py`. **4788 passed, 0 failed**, 4 skipped, 3 xpassed in 142s.
+
+### Pre-release verification
+
+- `pytest tests/` — green
+- Live browser-verified at port 8789 against stage-316:
+  - `window.smd` resolves to streaming-markdown module (PR #1851)
+  - `Content-Security-Policy: ...connect-src 'self' https://cdn.jsdelivr.net...` in served headers (PR #1852)
+  - `renderMd()` produces `<div class="katex-block">` for `\[...\]` and `<span class="katex-inline">` for `\(...\)` with no raw delimiter leakage (PR #1848)
+
 ## [v0.51.21] — 2026-05-07 — 3-PR batch (P0 hotfix + auto-compression UI + shell route HTML fallback)
 
 ### Fixed (3 PRs)
diff --git a/ROADMAP.md b/ROADMAP.md
index 3f287f68..3fe161cc 100644
--- a/ROADMAP.md
+++ b/ROADMAP.md
@@ -2,7 +2,7 @@
 
 > Web companion to the Hermes Agent CLI. Same workflows, browser-native.
 >
-> Last updated: v0.51.21 (May 7, 2026) — 4810 tests collected — 3-PR batch (P0 hotfix for v0.51.20 #1828 double-404 regression, auto-compression running indicator, shell route HTML fallback)
+> Last updated: v0.51.22 (May 7, 2026) — 4815 tests collected — 3-PR batch (P0 markdown streaming hotfix, CSP source-map allowance, LaTeX delimiter rendering)
 > Test source: `pytest tests/ --collect-only -q`
 > Per-version detail: see [CHANGELOG.md](./CHANGELOG.md)
 
diff --git a/TESTING.md b/TESTING.md
index d52b3f1f..f8ef4750 100644
--- a/TESTING.md
+++ b/TESTING.md
@@ -1835,8 +1835,8 @@ Bridged CLI sessions:
 
 ---
 
-*Last updated: v0.51.21, May 7, 2026*
-*Total automated tests collected: 4810*
+*Last updated: v0.51.22, May 7, 2026*
+*Total automated tests collected: 4815*
 *Regression gate: tests/test_regressions.py*
 *Run: pytest tests/ -v --timeout=60*
 *Source: <repo>/*