fix(web): address web card review — panel body, ol numbering, safe links, docs

- DetailsPanel: render the flattened result content below the web card, so a
  web_fetch's fetched body (and a search's answer/source markdown) stays
  visible on the panel's single-call reading surface — the card is a summary.
- WebBlock: the collapsed source tail keeps each source's original citation
  number via <li value>, and the expand control is a marker-less <li> so the
  <ol> is valid HTML; an empty-hostname URL (file:/data:) falls back to the raw
  URL so a label is never blank.
- web-row / GenericToolCard: both spread WebBlock uniformly with maxSources
  (fetch ignores it, like TerminalBlock's maxLines), dropping the duplicated
  per-kind conditional.
- Docs: WebBlock added to the ui-primitives README (both languages) with a Web
  retrieval section; the ui-conversation README's "inline licensed for this
  intent alone" claim de-absolutized and a web-card paragraph added; the Agent
  Note's safe-link description corrected to the http(s) subset of MarkdownText's
  allowlist (mailto excluded). Fixture source comment aligned with its data.
- Tests: ol numbering + marker-less expander, empty-hostname label fallback,
  the fetched body visible in the panel.

packages/client/ui-primitives/README.i18n.yaml

@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write packages/client/ui-primitives/README.md
-README.md: 0ef3c20f848b3d331c007911d0837f11cd72c024
-README.zh.md: af94551bfb9e12dbadcef6a96a54f9bf7ea71299
+README.md: b5b79f7f0d01afb2d06fb18bf30131cbdda75ca2
+README.zh.md: b10183496479249346da5da808f5ab3b6d2eef67