docs: Sprint 16.1 — _DAILY_LIMIT 140 → 45 follow-up across all 6 running docs

Sprint 16.1 (commit 11cfd46) is a one-line fix that lowers
_DAILY_LIMIT in backend/app/api/recipe_search.py:48 from
140.0 to 45.0. The 140 value was set assuming Spoonacular's
free tier is 150 pts/day; Sprint 15 round 1 proved the real
cap is 50 pts/day. The gate now triggers at 45 (5pt safety
margin), preventing the user from making requests that
would 503 after a 402 upstream roundtrip.

This commit updates the 6 running docs that track sprints:

- .agent/plan.md — Sprint 16.1 section appended to the
  Sprint 16 sections.
- .agent/context.md — Sprint 16.1 decisions + file:line
  references added.
- Review/sprint16-verification.md — Sprint 16.1 section
  appended (one-line change + verification).
- Review/ui-nielsen-audit.md — Sprint 16.1 paragraph added
  to the Sprint 16 status block.
- fix-ui-audit.md — T9.6 added to the Sprint 16 section.
- Review/handoff-ui-audit.md — TL;DR Sprint 16.1 line
  added, Last-updated footer updated.
- docs/HANDOFF.md — Tracking docs reference updated to
  include Sprint 16.1, Last-updated footer updated.

All 6 docs now reflect Sprint 16.1.

Review/handoff-ui-audit.md

@@ -38,6 +38,7 @@ If you are a new agent continuing this work, do this **in order**:
 - **Sprint 15 Round 2 (2026-06-07):** +18 recipes via `scripts/seed_recipes_round2.py`. Library at 67 total. LLM test for week 2026-07-20: `picked_count=0 / filled_count=21 / failed_count=0` (library now covers all 21 slots of a week). Awaiting commit + push.
 - **Sprint 15 Round 3 (2026-06-07):** +10 recipes via re-running `scripts/seed_recipes.py` (idempotent — skipped 37 duplicates). Library at 77 total. LLM test for week 2026-08-03: `picked_count=0 / filled_count=21 / failed_count=0`. **Library well past the 4-week coverage threshold.** Awaiting commit + push.
 - **Sprint 16 (Fix Sprint 13 LLM-model latent bug) code complete on 2026-06-08.** Discovered while answering "is there anything else to refine?" — every `/api/llm/plan` call has returned `picked_count=0` since 2026-06-05 because `kimi-k2.6:cloud` is a reasoning model that burns the `max_tokens` budget on internal `reasoning`. Library fill (Sprint 6+) silently took over. Two-line fix: switch `OLLAMA_MODEL` to `gpt-oss:20b`; bump `max_tokens` to 4000. + `frontend/src/api/llm.test.ts` (4 cases). Live verification: 5/5 test weeks return `picked_count` 15-21 (was 0/5 before). Awaiting commit + push.
+- **Sprint 16.1 (2026-06-08):** one-line `_DAILY_LIMIT` follow-up. `recipe_search.py:48` 140 → 45 (corrects the Spoonacular free-tier cap from 150 to 50, with 5pt safety margin). Awaiting commit + push.
 - Pre-existing repo issues: 1 failing test (`test_filter_blocks_by_cost` — verified pre-Sprint 8), `.gitignore` `lib/` bug, no CI. Documented.
 
 ---
@@ -467,4 +468,4 @@ cd frontend && npm run build
 
 Trust the build output. Trust the smoke checklist. Don't trust the deployment host's UI until the user confirms. The verification model is "I shipped, you verified, you reported, I fixed" — the agent in this role never sees the live UI directly.
 
-**Last updated: 2026-06-08** — Sprint 1 deployed; Sprints 2-6 awaiting user deploy; **Sprint 7 (`09c7525`), Sprint 8 (`efd1fc6`), Sprint 9 (F1 Onboarding Tour) + post-deploy fix (`1562929`), Sprint 10 (Deny Forever on Recipes), Sprint 11 (Wire the dead "Generate Meal Plan" CTA), Sprint 12 (F8 Spoonacular search), and Sprint 13 (F9-lite Ollama Cloud plan synthesis) committed on 2026-06-05, awaiting user deploy; Sprint 14 (Vitest for `useOnboarding`) committed on 2026-06-05, awaiting user push; Sprint 15 (Seed 50 family-friendly recipes + Sprint 12 latent-bug fix) code complete on 2026-06-06, 18 recipes imported, awaiting user commit + push; Sprint 15 Round 2 (committed 2026-06-07, awaiting user push) +18 recipes; Sprint 15 Round 3 (committed 2026-06-07, awaiting user push) +10 recipes; library at 77 total; **Sprint 16 (code complete 2026-06-08, awaiting user commit + push) — switches `OLLAMA_MODEL` from `kimi-k2.6:cloud` to `gpt-oss:20b` + bumps `max_tokens` to 4000; 11/11 tests green; live 5/5 test weeks return `picked_count` 15-21 (was 0/5 before)**. See the "How to take over" and "Pending user deploy" sections at the top of this file.
+**Last updated: 2026-06-08** — Sprint 1 deployed; Sprints 2-6 awaiting user deploy; **Sprint 7 (`09c7525`), Sprint 8 (`efd1fc6`), Sprint 9 (F1 Onboarding Tour) + post-deploy fix (`1562929`), Sprint 10 (Deny Forever on Recipes), Sprint 11 (Wire the dead "Generate Meal Plan" CTA), Sprint 12 (F8 Spoonacular search), and Sprint 13 (F9-lite Ollama Cloud plan synthesis) committed on 2026-06-05, awaiting user deploy; Sprint 14 (Vitest for `useOnboarding`) committed on 2026-06-05, awaiting user push; Sprint 15 (Seed 50 family-friendly recipes + Sprint 12 latent-bug fix) code complete on 2026-06-06, 18 recipes imported, awaiting user commit + push; Sprint 15 Round 2 (committed 2026-06-07, awaiting user push) +18 recipes; Sprint 15 Round 3 (committed 2026-06-07, awaiting user push) +10 recipes; library at 77 total; **Sprint 16 (code complete 2026-06-08, awaiting user commit + push) — switches `OLLAMA_MODEL` from `kimi-k2.6:cloud` to `gpt-oss:20b` + bumps `max_tokens` to 4000; 11/11 tests green; live 5/5 test weeks return `picked_count` 15-21 (was 0/5 before); Sprint 16.1 (2026-06-08) — one-line `_DAILY_LIMIT` 140 → 45**. See the "How to take over" and "Pending user deploy" sections at the top of this file.