Fix Feature 12 review findings F2–F8 on Regular grounding and onboarding

Grounding (F2–F5):
- Each ground_dinner job carries the dinner's new grounding_revision
  (migration 0010). Renaming a pending Regular raises the revision, and a
  job only grounds and writes a dinner still at its revision, so a queued
  original job no longer grounds the new name or decides the outcome.
- Background grounding keeps a method, minutes or difficulty a member saved
  while the Regular was pending, and fills only those left empty.
- Grounding by hand clears the pasted recipe_url, and link deduplication
  uses the source_url of the attached recipe, else the pending link.
- Archived dinners are not grounded: the job checks before any search,
  fetch or model call, and its final update requires an unarchived row.

Onboarding (F6, F7):
- Step 3 shows "Add Regulars" back to step 2 when the server refuses to
  finish with fewer than three Regulars.
- Common picks are hidden by a copy of harness Normalize/Similar, checked
  against the same shared cases as the Go code.

Docs (F8): ARCHITECTURE.md covers the three-Regular minimum, step-3
recovery, the grounding revision and the dedupe rules.

F1 was fixed in 1304487; its test now also asserts the old link is never
grounded and recipe_url stays cleared.

Maestro task 5037ff86-181d-448e-927b-c2fd2258a25d.

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

migrations/queries/dinners.sql

@@ -25,10 +25,13 @@ SELECT COUNT(*) FROM dinners
 WHERE status = 'regular';
 
 -- name: ListUnarchivedDinners :many
--- Every dinner a new or renamed dinner must not repeat.
-SELECT * FROM dinners
-WHERE status <> 'archived'
-ORDER BY id;
+-- Every dinner a new or renamed dinner must not repeat, with the
+-- source_url of the recipe it is grounded in (NULL while it has none).
+SELECT sqlc.embed(dinners), recipes.source_url AS recipe_source_url
+FROM dinners
+LEFT JOIN recipes ON recipes.id = dinners.recipe_id
+WHERE dinners.status <> 'archived'
+ORDER BY dinners.id;
 
 -- name: UpdateDinner :one
 -- An unknown id returns sql.ErrNoRows.
@@ -45,6 +48,7 @@ SET name = ?,
 	recipe_url = ?,
 	photo_id = ?,
 	grounding_status = ?,
+	grounding_revision = ?,
 	updated_by = ?,
 	updated_at = ?
 WHERE id = ?
@@ -78,10 +82,12 @@ WHERE id = ?
 RETURNING *;
 
 -- name: GroundDinner :one
--- Records a dinner's grounding (grounded or manual) and clears any
--- grounding_error. An unknown id returns sql.ErrNoRows.
+-- Records a dinner's grounding by hand (grounded or manual) and clears any
+-- grounding_error and pasted recipe_url: the recipe chosen replaces the
+-- link. An unknown id returns sql.ErrNoRows.
 UPDATE dinners
 SET recipe_id = ?,
+	recipe_url = NULL,
 	photo_id = ?,
 	method = ?,
 	minutes_total = ?,
@@ -94,35 +100,44 @@ WHERE id = ?
 RETURNING *;
 
 -- name: GroundPendingDinner :execrows
--- Records the background grounding of a dinner still pending under the
--- normalized name it was grounded for; a dinner grounded some other way or
--- renamed meanwhile is left as it is (0 rows).
+-- Records the background grounding of an unarchived dinner still pending at
+-- the grounding_revision it was grounded for; a dinner grounded some other
+-- way, renamed or archived meanwhile is left as it is (0 rows). A method,
+-- minutes_total or difficulty already set is kept: a pending dinner has
+-- them only when a member edited them while it was grounding.
 UPDATE dinners
-SET recipe_id = ?,
-	photo_id = ?,
-	method = ?,
-	minutes_total = ?,
-	difficulty = ?,
+SET recipe_id = sqlc.arg(recipe_id),
+	photo_id = sqlc.arg(photo_id),
+	method = COALESCE(method, sqlc.arg(method)),
+	minutes_total = COALESCE(minutes_total, sqlc.arg(minutes_total)),
+	difficulty = COALESCE(difficulty, sqlc.arg(difficulty)),
 	grounding_status = 'grounded',
 	grounding_error = NULL,
-	updated_at = ?
-WHERE id = ? AND grounding_status = 'pending' AND normalized_name = ?;
+	updated_at = sqlc.arg(updated_at)
+WHERE id = sqlc.arg(id)
+	AND status <> 'archived'
+	AND grounding_status = 'pending'
+	AND grounding_revision = sqlc.arg(grounding_revision);
 
 -- name: FailPendingDinnerGrounding :execrows
--- Records why the background grounding of a dinner still pending under the
--- normalized name it was grounded for failed; a dinner grounded some other
--- way or renamed meanwhile is left as it is (0 rows).
+-- Records why the background grounding of an unarchived dinner still
+-- pending at the grounding_revision it was grounded for failed; a dinner
+-- grounded some other way, renamed or archived meanwhile is left as it is
+-- (0 rows).
 UPDATE dinners
 SET grounding_status = 'failed',
 	grounding_error = ?,
 	updated_at = ?
-WHERE id = ? AND grounding_status = 'pending' AND normalized_name = ?;
+WHERE id = ?
+	AND status <> 'archived'
+	AND grounding_status = 'pending'
+	AND grounding_revision = ?;
 
 -- name: FailOrphanedPendingDinnerGroundings :execrows
--- Fails every dinner still pending whose grounding job is no longer queued
--- or running: the process stopped before the job, or before its handler
--- recorded a result. Run at boot, after the job runner fails the jobs a
--- previous process left running.
+-- Fails every dinner still pending whose grounding job for its current
+-- grounding_revision is no longer queued or running: the process stopped
+-- before the job, or before its handler recorded a result. Run at boot,
+-- after the job runner fails the jobs a previous process left running.
 UPDATE dinners
 SET grounding_status = 'failed',
 	grounding_error = sqlc.arg(grounding_error),
@@ -133,4 +148,5 @@ WHERE grounding_status = 'pending'
 		WHERE jobs.kind = sqlc.arg(kind)
 			AND jobs.status IN ('queued', 'running')
 			AND json_extract(jobs.payload, '$.dinner_id') = dinners.id
+			AND json_extract(jobs.payload, '$.revision') = dinners.grounding_revision
 	);