Show idea job results' sources safely on every read

GET /jobs/{id} served a succeeded idea job's stored result as it was, so
a result stored before sources were made safe still showed a
token-bearing source_url and a site_name taken from the link's host
(BASE-01-R1). jobs.Kind.FailedResult becomes ShownResult, applied to
every stored result with the job's status: ideas_from_ingredients and
quick_ideas results show no ideas when failed and, otherwise, each
idea's source through dinners.SourceOf, the one rule, so no job old or
new serves an unsafe source. Other kinds' results are untouched.

dinners.SourceOf now parses the link before reading the site name, so a
link that does not parse is an error with or without a stored name, and
an idea job grounded in one fails instead of succeeding (BASE-01-R2).

Task: c15ed4b5-25ae-43c6-8d36-f4a6dd51e5af

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

internal/ideas/ideas.go

@@ -124,18 +124,18 @@ func NewService(st *store.Store, grounder *recipes.Grounder, generate Generator,
 	}
 	s := &Service{st: st, grounder: grounder, runner: runner, generate: generate, quick: quick, logger: logger}
 	var err error
-	if s.job, err = register(runner, KindFromIngredients, s.run, withoutIdeas[Result]); err != nil {
+	if s.job, err = register(runner, KindFromIngredients, s.run, shownJobResult[Result]); err != nil {
 		return nil, err
 	}
-	if s.quickJob, err = register(runner, KindQuick, s.runQuick, withoutIdeas[QuickResult]); err != nil {
+	if s.quickJob, err = register(runner, KindQuick, s.runQuick, shownJobResult[QuickResult]); err != nil {
 		return nil, err
 	}
 	return s, nil
 }
 
-// register registers the service-only job name, run by run, whose failed
-// jobs show their result through failed.
-func register[P any, R jobs.Public](runner *jobs.Runner, name string, run jobs.Handler[P, R], failed func(json.RawMessage) (json.RawMessage, error)) (*jobs.Kind[P], error) {
+// register registers the service-only job name, run by run, whose jobs
+// show their result through show.
+func register[P any, R jobs.Public](runner *jobs.Runner, name string, run jobs.Handler[P, R], show func(jobs.Status, json.RawMessage) (json.RawMessage, error)) (*jobs.Kind[P], error) {
 	kind, err := jobs.Register(runner, name, run, Reasons...)
 	if err != nil {
 		return nil, err
@@ -143,7 +143,7 @@ func register[P any, R jobs.Public](runner *jobs.Runner, name string, run jobs.H
 	if err := kind.ServiceOnly(); err != nil {
 		return nil, err
 	}
-	if err := kind.FailedResult(failed); err != nil {
+	if err := kind.ShownResult(show); err != nil {
 		return nil, err
 	}
 	return kind, nil
@@ -254,6 +254,9 @@ type shownResult[R any] interface {
 	shown() int
 	// cleared is the result showing no ideas.
 	cleared() R
+	// withSafeSources is the result with each idea's source as
+	// shownSource gives it.
+	withSafeSources() (R, error)
 }
 
 func (r Result) shown() int { return len(r.Ideas) }
@@ -263,11 +266,25 @@ func (r Result) cleared() Result {
 	return r
 }
 
+func (r Result) withSafeSources() (Result, error) {
+	ideas := make([]Idea, len(r.Ideas))
+	for i, idea := range r.Ideas {
+		src, err := shownSource(idea.SourceURL, idea.SiteName)
+		if err != nil {
+			return Result{}, fmt.Errorf("ideas: idea %d: %w", i, err)
+		}
+		idea.SourceURL, idea.SiteName = src.URL, src.SiteName
+		ideas[i] = idea
+	}
+	r.Ideas = ideas
+	return r, nil
+}
+
 // finish ends a job whose work returned res and err. A job that failed
 // has its result published again with no ideas, to tidy the stored
 // result. That write is not what keeps a failed job from showing ideas,
 // since it may fail and a job interrupted by restart never makes it:
-// withoutIdeas, applied whenever a failed job is read, is.
+// shownJobResult, applied whenever a failed job is read, is.
 func finish[R shownResult[R]](ctx context.Context, logger *slog.Logger, what string, res R, err error, publish func(R) error) (R, error) {
 	var zero R
 	if err == nil {
@@ -412,15 +429,24 @@ func ground(ctx context.Context, g *recipes.Grounder, reqs []recipes.GroundReque
 	return failed
 }
 
-// withoutIdeas is a failed job's stored result as the job shows it: with no
-// ideas, however the job failed, so a failed job never shows ideas kept
-// before the failure.
-func withoutIdeas[R shownResult[R]](stored json.RawMessage) (json.RawMessage, error) {
+// shownJobResult is a job's stored result as the job shows it. A failed
+// job's shows no ideas, however the job failed, so a failed job never
+// shows ideas kept before the failure. Any other job's shows each idea's
+// source as shownSource gives it, so a result stored before sources were
+// made safe never shows a link or name that could leak a secret.
+func shownJobResult[R shownResult[R]](status jobs.Status, stored json.RawMessage) (json.RawMessage, error) {
 	var res R
 	if err := json.Unmarshal(stored, &res); err != nil {
-		return nil, fmt.Errorf("ideas: decode failed job's result: %w", err)
+		return nil, fmt.Errorf("ideas: decode %s job's result: %w", status, err)
 	}
-	return res.cleared().PublicJSON()
+	if status == jobs.StatusFailed {
+		return res.cleared().PublicJSON()
+	}
+	safe, err := res.withSafeSources()
+	if err != nil {
+		return nil, err
+	}
+	return safe.PublicJSON()
 }
 
 // ideaOf is idea as grounded by gr.
@@ -456,6 +482,24 @@ func sourceOf(gr recipes.Grounded) (dinners.Source, error) {
 	return src, nil
 }
 
+// shownSource is the source of an idea as stored in a job's result, with
+// link sourceURL and site name siteName, as a client may see it (see
+// dinners.SourceOf). A result stored now already holds it, and one stored
+// before sources were made safe holds the grounded recipe's own, with ""
+// for no site name, as sourceOf reads it; a null link, which only a result
+// stored now holds, is checked as "".
+func shownSource(sourceURL, siteName *string) (dinners.Source, error) {
+	var link string
+	if sourceURL != nil {
+		link = *sourceURL
+	}
+	var site sql.NullString
+	if siteName != nil {
+		site = sql.NullString{String: *siteName, Valid: *siteName != ""}
+	}
+	return dinners.SourceOf(site, link)
+}
+
 // QuickJob is the KindQuick payload: the kind of Quick dinner wanted,
 // skills.QuickCrockpot or skills.QuickUnder30, and the names already shown
 // to the household, as skills.CleanExclude returns them.
@@ -526,6 +570,20 @@ func (r QuickResult) cleared() QuickResult {
 	return r
 }
 
+func (r QuickResult) withSafeSources() (QuickResult, error) {
+	ideas := make([]QuickIdea, len(r.Ideas))
+	for i, idea := range r.Ideas {
+		src, err := shownSource(idea.SourceURL, idea.SiteName)
+		if err != nil {
+			return QuickResult{}, fmt.Errorf("ideas: idea %d: %w", i, err)
+		}
+		idea.SourceURL, idea.SiteName = src.URL, src.SiteName
+		ideas[i] = idea
+	}
+	r.Ideas = ideas
+	return r, nil
+}
+
 // OfQuickKind reports whether a recipe cooked by method in minutes (nil
 // when unknown) is a Quick dinner of kind: for skills.QuickCrockpot,
 // cooked in a crock pot (normalize_recipe writes a slow cooker as