fix(#4657): give the ui consideration probe a text_en language channel (#4804)

* test(#4657): add failing-first coverage for the ui probe's text_en channel

Mirrors the #3717/#4156 test shape onto the UI adapter: a failing-first
proposeConsiderations regression (Danish text + English text_en must classify
as its English equivalent, not land in the #1110 unclassified sentinel),
proposeElements/analyzeCoverage/CLI end-to-end pairs, fail-closed text_en
validation cases (empty/whitespace/non-string, unconditional under an
elements override), a ui-phase.md Step 9.5 workflow-prose contract test, a
reference-doc Inputs parity test, and a fast-check property proving any
cue-matching prose classifies identically under a cue-free Danish rendering
plus text_en. All new assertions are RED until src/ui-consideration-probe.cts
and the workflow/reference docs are updated.

* fix(#4657): give the ui consideration probe a text_en language channel

Element gains an optional text_en; classifyElement's own signature stays
untouched (a locked, directly-tested export) and the text_en ?? text
selection is pushed to the two classification call sites (proposeConsiderations,
proposeElements) instead. text_en is validated fail-closed: an empty or
whitespace-only value throws rather than silently winning the ?? fallback and
degrading classification to zero kinds.

Mirrors #3717/#4156 onto the UI adapter: ui-phase.md Step 9.5 gains the
Non-English projects section (mirroring spec-phase Step 5.5) and the
ELEMENTS_JSON shape comment documents the field with both zero-applicable
guard arms named; the reference doc's Inputs section, the PROBE.ui CONTEXT
predicate (with both derived indexes regenerated), and the nav-override
test expectation stay in sync. The ui-phase contract test carries the
site-scoped allow-test-rule marker and its cluster is registered in the
test-file-count allowlist ratchet.

Emitted-Drift-Ack-Growth: ui-phase.md — Non-English text_en section, ELEMENTS_JSON shape comment, and two-arm guard wording (#4657)

* docs(#4657): backfill changeset PR number

---------

Co-authored-by: sim <sim@local>

CONTEXT.md

@@ -614,6 +614,7 @@ The prompt-level data/instruction isolation seam for untrusted web/document ingr
 `PROBE.prohib.verification=test|judgment`
 `PROBE.ui.verification=explicit|backstop`
 `PROBE.ui.axis=MIXED — closed compiled shape-rooted 8 (empty/loading/error/populated/partial/overflow/zero-one-many/long-text) via ui-consideration-probe adapter; open UX (real-time/a11y/i18n-RTL) prose-owned in references/domain-probes.md, NOT compiled (#1867)`
+`PROBE.ui.text_en=optional English translation of Element.text read by classification (text_en ?? text), engine input never user-facing output; mirrors the edge adapter's #3717 field; empty/whitespace/non-string fails closed (#4657)`
 `PROBE.ui.seam=ui-phase Step 9.5 post-verification: element-cue classify -> propose-then-confirm (partial-cue mitigation, Goodhart) -> autoResolve --auto floor (never dismiss; unclassified stays unresolved #1110) -> ## UI Considerations write-back -> plan-phase `## UI Considerations` lift rule (#1867)`
 `PROBE.ci.surface=the contract (parse/validate, projection round-trip, fail-closed guards), NEVER the LLM judgment (ADR-550 D5)`
 `PROHIB.recall=LLM-prose; no compiled prohibition-probe recall engine (only the schema/projection layer is code, ADR-550 D7b)`