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/api/admin_status.go

@@ -10,7 +10,7 @@ import (
 	"git.fabledsword.com/bvandeusen/minstrel/internal/logging"
 )
 
-// The admin Overview's status sections (M504): after the verdict, who is
+// The admin Overview's status sections: after the verdict, who is
 // listening, what is downloading, what the library holds and how much room
 // it has, and how the server itself is doing. One read for the page, polled
 // while it is open.