docs(web,readme): taste pass — fix stale refs, tighten design rhythm

Polish fixes (12):
- INSTALL.md: drop duplicate code block; doc CODEWHALE_VERSION canonical
  env var; fix example mirror URLs /DeepSeek-TUI/ → /CodeWhale/; remove
  stale "Once npm publication resumes" conditional
- footer.tsx: fix Gitee mirror URL deepseek-tui → CodeWhale
- globals.css: update seal CSS shadows from old cream rgba(244,241,232)
  to paper white rgba(255,255,255)
- web/README.md: update palette description cream #FAF6EE → white #FFFFFF
- nav.tsx: fix zh-only date strip (第…期) and API label (在线) — now
  "Edition …" / "API · Online" in en mode
- page.tsx: hardcoded v0.8.56 → dynamic facts.version
- README.md: merge duplicate Contributing sections
- README.ja-JP/vi: parenthesize untranslated Chinese thank-you blurbs

Design rhythm (9):
- ThinkingTrace section: py-16→py-20, bg-paper-deep, hairlines for reveal
- Judgment stack: py-16→py-12; middle cell bg-paper-deep for ABA rhythm
- Maintainer loop: py-16→py-14; step numbers grow 01→04
- How it works: py-16→py-12
- Join in closer: py-16→py-20 (dark section breathes)
- Ticker: LIVE label shrunk to annotation weight

web/app/globals.css

@@ -155,8 +155,8 @@ h3 { font-size: 1.18rem; line-height: 1.25; }
   border-radius: 1px;
   letter-spacing: -0.04em;
   box-shadow:
-    inset 0 0 0 1px rgba(244,241,232,0.18),
-    inset 0 0 0 3px var(--ink);
+     inset 0 0 0 1px rgba(255,255,255,0.18),
+     inset 0 0 0 3px var(--ink);
   transform: rotate(-1.5deg);
   position: relative;
 }
@@ -165,7 +165,7 @@ h3 { font-size: 1.18rem; line-height: 1.25; }
   position: absolute;
   inset: -1px;
   background:
-    radial-gradient(rgba(244,241,232,0.35) 1px, transparent 1px) 0 0 / 4px 4px;
+    radial-gradient(rgba(255,255,255,0.35) 1px, transparent 1px) 0 0 / 4px 4px;
   mix-blend-mode: screen;
   border-radius: 1px;
   pointer-events: none;
@@ -175,8 +175,8 @@ h3 { font-size: 1.18rem; line-height: 1.25; }
 .seal-indigo {
   background: var(--indigo);
   box-shadow:
-    inset 0 0 0 1px rgba(244,241,232,0.22),
-    inset 0 0 0 3px var(--indigo);
+     inset 0 0 0 1px rgba(255,255,255,0.22),
+     inset 0 0 0 3px var(--indigo);
 }
 
 /* ---------- pills / status ---------- */