Add ideas_from_ingredients skill and job

Implement the ideas_from_ingredients v1 skill on the AI harness: it asks
for 8 ideas {name, uses[], missing[], est_minutes, method, difficulty,
search_query}, keeps only "uses" entries whose harness.Normalize form is
one of the household's listed ingredients (written as the household wrote
them, in its order), drops ideas using none or repeating another, and
computes the summary line from the corrected lists.

Add internal/ideas: an ideas_from_ingredients job that grounds the ideas
with Grounder.GroundMany in the model's order until 5 are kept, drops the
ungroundable ones and, for quick_only, those whose grounded recipe is not
a Quick dinner (crockpot or minutes_total <= 30), publishing the result
as each idea is kept. POST /api/v1/ideas/from-ingredients answers 202
{jobId}.

Maestro task c3c5f98e-7f7d-4c6b-a1ab-d45bb8e497f9.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/ARCHITECTURE.md

@@ -308,6 +308,28 @@ automatic** (D-021).
   still `pending` or `running` with no job queued or running (the process
   stopped, or recording its end failed) is set `failed`, so it does not
   block the next.
+- Cook from what I have (`ideas.Service`, Feature 18). `POST
+  /api/v1/ideas/from-ingredients {ingredients[], quick_only}` (both
+  required) checks the list with `skills.CleanIngredients` — 1 to 20
+  entries, each non-blank, at most 80 characters, with a non-empty
+  `harness.Normalize` form that no earlier entry shares — answering 400
+  `invalid_request` otherwise, then enqueues an `ideas_from_ingredients`
+  job (service-only: `POST /jobs` refuses the kind) and answers 202
+  `{jobId}` without waiting. The job runs `ideas_from_ingredients` (scope:
+  `skills.IdeasScope`, the flag and the normalized list in order), then
+  grounds its ideas in the model's order with `Grounder.GroundMany`, as
+  many as are still wanted at a time, until 5 are kept or none are left.
+  An idea no recipe grounds is dropped; with `quick_only`, so is one whose
+  grounded recipe is not a Quick dinner (`ideas.IsQuick`: method
+  `crockpot`, or `minutes_total` ≤ 30 — the recipe's, never the model's
+  `est_minutes`). Ideas are not stored as dinners. The job publishes
+  `{stage, ingredients, quick_only, ideas: [{name, uses, missing, summary,
+  method, minutes_total, difficulty, quick, recipe_id, photo_url,
+  source_url, site_name}], dropped}` at each stage (`suggesting`,
+  `grounding`, `done`) and again each time an idea is kept, so the result
+  fills as the ideas ground; it may end `done` with no ideas. It fails
+  with `ai_failed` (the skill or `normalize_recipe` failed; no idea is
+  made up instead, D-017), `search_not_configured` or `search_failed`.
   `GET /api/v1/suggestions/deck` returns `{suggestions: [{id, dinner_id,
   name, photo_url, difficulty, method, minutes_total, cuisine, reason,
   cited_regular_ids, status, dinner_status, decided_at, created_at}],
@@ -470,6 +492,22 @@ automatic** (D-021).
   not a Regular; and one whose reason is over 180 characters or names none
   of its cited Regulars. Cited names are rewritten as the household writes
   them. Grounding each survivor in a recipe is the caller's next step.
+- **Ideas from ingredients** (`skills.IdeasFromIngredients`, skill
+  `ideas_from_ingredients` v1): from the household's ingredient list (the
+  "Ingredients on hand" context section) and the Quick only flag, asks for
+  8 ideas `{name, uses[], missing[], est_minutes, method, difficulty,
+  search_query}` at the household temperature. Malformed replies (a
+  missing field, a bad enum, an empty name, more than 8 ideas) get the one
+  repair turn. The invariant is enforced in Go: a `uses` entry is kept
+  only when its `harness.Normalize` form is a listed ingredient's, and is
+  then written as the household wrote it, once, in the household's order;
+  `missing` loses blanks, repeats and anything listed. An idea left using
+  none of the listed ingredients, or repeating an earlier idea
+  (`harness.Similar`), is dropped into `Dropped`. Each kept idea's summary
+  line (`skills.IdeaSummary`) is computed from the corrected lists: "Uses
+  all 5 · missing: 1 lime" when every ingredient is used, "Uses 3 of 5 ·
+  missing: …" otherwise, with "nothing missing" in place of the list when
+  nothing is.
 - **Supply run titles** (`skills.TitleArchive`, skill `archive_title`
   v1): from the names of the week's planned dinners in day order, writes
   `{title}`, the Supply run's post title in the Supply archive, at the