fix(rectification): invite another dated event instead of saying the pool is closed (BUG-689)

When the seven collect lines are closed, the range card still appears, but the copy asks for one more exact-day event of any kind instead of saying the questions are finished. A new dated event after delivery stales the snapshot so the session does not stay delivered.

frontend/DESIGN.md

@@ -234,7 +234,7 @@ The birth-time rectification session is the consultation transcript plus a house
 | `question-gap`, delivered | no current question, or the current question is a dead choice card, and the session already delivered a range (`completed_with_range` / `provisional_range` / adopt outcomes, or `tied_first`); range card or range line plus an exit note. Never “没有拿到下一个问题。” | enabled |
 | `verified_idle` | one closing line `postAdoptVerifyDone` under the still-visible range card (same assistant column); no spinner, no reload | enabled |
 | `choice-pending` | the answered card (`data-selected` fill, a top row “正在记录…”) and the same live row from “正在记录本次选择…” through the follow-up turn | enabled (typing queues), stop visible |
-| `candidates` | one range-delivery card titled “目前范围 …（对照了 N 件经历）”, a caption under the title that only names still-open lines (or “能问的都问完了”); optional “再答两道参考题微调排序” only when unused D9/D10 remain; if those were already asked and the top two are still within one point, a line “这两分钟按现有信息分不开，参考题已经用过。”; then up to three compare columns (highest posterior first; “更像这个” adopts); a closed “查看验证报告” fold. On a normal convergence, unused style questions are asked before this card. Exhausted and closed-ceiling exits still deliver the card if a style question cannot be rendered. | enabled |
+| `candidates` | one range-delivery card titled “目前范围 …（对照了 N 件经历）”, a caption under the title that only names still-open lines; when the top two relative likelihoods are within 3 points and collect lines are closed, a body-size invite to add one more event of any kind, asking for an exact day first then falling back to year-month (never “能问的都问完了”); optional “再答两道参考题微调排序” only when unused D9/D10 remain; if those were already asked and the top two are still within one point, a line “这两分钟按现有信息分不开，参考题已经用过。”; then up to three compare columns (highest posterior first; “更像这个” adopts); a closed “查看验证报告” fold. On a normal convergence, unused style questions are asked before this card. Exhausted and closed-ceiling exits still deliver the card if a style question cannot be rendered. | enabled |
 | `adopting` | “正在采用 HH:MM…” through the follow-up turn | enabled (typing queues), stop visible |
 | `confirmed` | “已确认校正时间：HH:MM” | enabled |
 | `readonly` | “该校正已结束，只能查看历史。” and “再次校正” | disabled |
@@ -253,7 +253,7 @@ The birth-time rectification session is the consultation transcript plus a house
 - **Accessibility:** native radio inputs remain focusable, every conditional field has a persistent label, status text uses live regions, and the complete flow is keyboard operable.
 - **Motion:** source-dependent fields enter with the existing 180ms opacity/vertical reveal; reduced-motion removes the translation.
 - **Life-event evidence:** after deterministic questionnaire completion, render three structured event rows by default and allow up to six. Each row uses a domain select, a precision select, and a matching year/month/day control; free-form descriptions are not part of scoring.
-- **Candidate result:** keep the reported range, candidate interval, and active-time status visually separate. Delivery shows one range card: title “目前范围 HH:MM–HH:MM（对照了 N 件经历）”, a caption “还能再收窄：如果记得 …” under the title, up to three compare columns (time, relative likelihood, D9/D10/nakshatra traits, event-fit counts, next-12-month windows, “更像这个”), and the representative-minute boundary. Collect copy “现在还剩 HH:MM–HH:MM 里 N 个候选” uses the same `credible_range` as the timeline “目前范围”, not the first/last active candidate minute. An eight-method report sits in a closed `<details>` fold. Support numbers stay on the house board. Low confidence keeps evidence editing open; medium offers save or add evidence; high uses a separate confirmation action and never labels a column as the true birth time.
+- **Candidate result:** keep the reported range, candidate interval, and active-time status visually separate. Delivery shows one range card: title “目前范围 HH:MM–HH:MM（对照了 N 件经历）”, a caption “还能再收窄：如果记得 …” under the title while collect lines remain open, up to three compare columns (time, relative likelihood, D9/D10/nakshatra traits, event-fit counts, next-12-month windows, “更像这个”), and the representative-minute boundary. When the top two columns are within 3 percentage points and the seven collect lines are closed, the card body (not the caption) invites one more dated event of any kind, with examples outside those lines. Collect copy “现在还剩 HH:MM–HH:MM 里 N 个候选” uses the same `credible_range` as the timeline “目前范围”, not the first/last active candidate minute. An eight-method report sits in a closed `<details>` fold. Support numbers stay on the house board. Low confidence keeps evidence editing open; medium offers save or add evidence; high uses a separate confirmation action and never labels a column as the true birth time.
 - **Evidence accessibility:** every row keeps visible labels, validation errors use live regions, add/remove controls retain 44px targets, and scoring/confirmation loading states disable duplicate submission without hiding the existing evidence.
 - **One-question guide:** the guided journey renders only the persisted `nextAction` and one server-selected question. A deterministic question is visible immediately; Agent wording may replace it without changing the question identity, domain, precision request, progress, or permissions. The composer explicitly permits an approximate year. Spoken collect does not render skip chips; typing 「没有」 still declines the domain and 「记不清」 still skips it. Stop on spoken collect is not a composer button: `CHOICE_STOP_LABEL` (“先这样，先看当前范围”) stays on choice cards, and generating turns keep “停止回答”. The readonly range line is a status sentence, not a stop control. Discriminator cards fold “为什么问这题” under the stem. Hovering or selecting an option does not reveal an `answer_impact` time line. The method sentence (`vargaSentence`) lives in the expanded activity timeline, not in the spoken bubble. The composer has no `rectification-step-state` status sentence and no `rectification-composer-meta`.
 - **Draft review:** natural-language answers become one inline review card. The evidence domain is read-only and uses its Chinese label; precision controls which exact year, month, or day input is available. Incomplete drafts keep edit and skip paths visible, while confirmation is disabled until the structured date is valid. Status and errors use polite or assertive live regions without clearing the persisted journey.