Apply the brand across the repo: reports, README, guide

* simurg/core/brand.py: single source of the mark geometry, colours, favicon
  and the report header band (scripts/brand now load it from there).
* HTML reports (QC report, compare dashboard, methylation QC): offline SVG
  favicon, indigo header band with the mark, version and a sha256 of the data
  shown; Noto Sans font stack; methylation plots in Okabe-Ito colours.
* README banner, guide logo, brand/blog links; branding brief updated to the
  final identity; Noto (OFL) and Okabe-Ito entries in THIRD_PARTY_NOTICES;
  CHANGELOG (Unreleased).

Unit tests + P5 QC oracle: 285 passed; ruff and mypy clean.

src/simurg/pipeline/compare.py

@@ -7,6 +7,7 @@ A and B are two files or two folders; folders are paired by relative path. Outpu
 from __future__ import annotations
 
 import gzip
+import hashlib
 import html
 import io
 import json
@@ -228,7 +229,8 @@ DASH_CSS = """
 :root{--bg:#fafafa;--fg:#222;--muted:#666;--line:#ddd;--ok:#d6e6f5;--near:#e8f2d6;--bad:#f9d3ac;--unk:#e6e6e6}
 @media (prefers-color-scheme: dark){:root{--bg:#1d1f21;--fg:#e6e6e6;--muted:#aaa;--line:#444;
   --ok:#23405c;--near:#35451f;--bad:#6b3d10;--unk:#3a3a3a}}
-body{margin:0;padding:16px;background:var(--bg);color:var(--fg);font:14px/1.4 system-ui,sans-serif}
+body{margin:0;background:var(--bg);color:var(--fg);font:14px/1.4 "Noto Sans",system-ui,sans-serif}
+.sa-main{padding:16px}
 table{border-collapse:collapse;margin:6px 0}
 td,th{border:1px solid var(--line);padding:3px 8px;text-align:right}
 td:first-child,th:first-child{text-align:left}
@@ -294,12 +296,18 @@ def render_dashboard(summary: dict[str, Any], examples: dict[str, list[dict[str,
                 + _table(["pair", "locus", "A", "B"], body)
             )
     parts.append('<p class="muted">Every discrepancy and every unmatched record is listed in discrepancies.tsv.gz.</p>')
+    from simurg.core.brand import BAR_CSS, favicon_link, report_bar
+
+    checksum = hashlib.sha256(json.dumps(summary, sort_keys=True, default=str).encode("utf-8")).hexdigest()
+    bar = report_bar("Differential test", __version__, "summary sha256", checksum)
     return (
         '<!doctype html><html lang="en"><head><meta charset="utf-8">'
         '<meta name="viewport" content="width=device-width, initial-scale=1">'
-        f"<title>{title} — {PRODUCT_NAME}</title><style>{DASH_CSS}</style></head><body>"
+        f"<title>{title} · {PRODUCT_NAME}</title>{favicon_link()}<style>{DASH_CSS}{BAR_CSS}</style></head><body>"
+        + bar
+        + '<div class="sa-main">'
         + "\n".join(parts)
-        + "</body></html>\n"
+        + "</div></body></html>\n"
     )