fix(client-web): reject unknown web kind, lock fixture to contract, observe web card in boot smoke

- webCardModel returns null for an unknown web `kind` (wire from a newer host)
  instead of drawing it as a malformed fetch, matching the unknown-`card` and
  terminal-model wire-boundary default.
- Fixture WEB_SEARCH_RESULT/WEB_FETCH_RESULT and the source type derive from the
  contract's ToolResultView via Extract, so a new contract field fails at the
  type level rather than drifting silently.
- built-boot smoke asserts the web_search/web_fetch turns render their keyed
  WebRow cards, giving the registration and wire projection an assembled check.
- DetailsPanel comment no longer claims the card omits content for search.
- ui-primitives README inline-Chinese limitation now lists WebBlock's controls.

packages/client/ui-primitives/README.md

@@ -29,5 +29,5 @@ None; this package neither assembles nor sends a provider request.
 - **Glyph-level icons are redrawn approximations** — the fish logo (and the sparkle held by ui-conversation) come from font glyphs whose vector geometry is not exportable from the local design data; hand-authored recreations stand in until an exact export path exists.
 - **Pill and Input have no design source** — both atoms are self-defined; the sidebar search field and view-tab strip that resemble them are consumer-owned compositions, not these atoms.
 - **StateDot `Active` variant is a hidden placeholder in the design** — not implemented; the four shipped states (done/warning/ongoing/error) are the complete P-I surface.
-- **This package's user-facing copy is inline Chinese, not localized** — the atoms are zero-cordis and so cannot reach `ctx.locale`; `TerminalBlock`'s exit-code and signal pills, its copy and expand controls, and `CodeBlock`'s copy control are all hardcoded. This matches the repo-wide state the locale package records (only the Settings surface is translated); extracting these into the `zh`/`en` dictionaries needs a localization channel for zero-cordis atoms and belongs to that repo-wide extraction.
+- **This package's user-facing copy is inline Chinese, not localized** — the atoms are zero-cordis and so cannot reach `ctx.locale`; `TerminalBlock`'s exit-code and signal pills, its copy and expand controls, `CodeBlock`'s copy control, and `WebBlock`'s source expand/collapse controls and its source-list and fetch truncation notes are all hardcoded. This matches the repo-wide state the locale package records (only the Settings surface is translated); extracting these into the `zh`/`en` dictionaries needs a localization channel for zero-cordis atoms and belongs to that repo-wide extraction.
 - **`TerminalBlock` is not a terminal emulator** — it renders settled or still-running command output, not an interactive session: SGR color and attributes are honored, and so are the in-line cursor movements a progress line uses — carriage return, backspace, erase-in-line, tab stops and character width. Absolute cursor positioning, screen clearing, and alternate-screen sequences are stripped. Basic-16 magenta and cyan have no token equivalent and stay literal rgb.