docs: api comments say what the endpoints do, not how they came to be (#6277)

Rewrites the internal/api comment blocks to rule 32: task, milestone and
rule ids gone, the stories behind them restated as the constraint they
left, stale references corrected (the stream secret is wired from config,
the timezone handler already refreshes the scheduler, the Android app is
the native client, the design docs cited are not in the repo). Also
rewraps comment lines over 80 columns left by the earlier batches.

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

internal/acquire/fanout.go

@@ -10,8 +10,8 @@ import (
 	"git.fabledsword.com/bvandeusen/minstrel/internal/indexer"
 )
 
-// Searching every source at once. A source that is down narrows a search rather than failing it: the
-// results come back with the list of who did not answer.
+// Searching every source at once. A source that is down narrows a search rather
+// than failing it: the results come back with the list of who did not answer.
 
 // SourceFailure is one source that could not be reached.
 type SourceFailure struct {

internal/acquire/pace.go

@@ -8,8 +8,9 @@ import (
 	"git.fabledsword.com/bvandeusen/minstrel/internal/indexer"
 )
 
-// SearchPace is the one Pacer every search shares. Process-wide because a Fanout is built fresh for each
-// search; a Pacer per Fanout would start empty and pace nothing.
+// SearchPace is the one Pacer every search shares. Process-wide because a
+// Fanout is built fresh for each search; a Pacer per Fanout would start empty
+// and pace nothing.
 var SearchPace = &Pacer{}
 
 // holdWithoutRetryAfter is how long a source that answered 429 without saying