post: generating subtitles for songs that ship without timestamps

Tutorial on turning untimed AI-generated audio into LRC + SRT: align ASR word
timestamps against the KNOWN lyrics (SequenceMatcher) instead of trusting a
transcript, then a governor that rejects impossible anchors, refills runs by
unit-proportional duration, and enforces a 1.2 s minimum line gap.

Ships 18 English songs (342 subtitle lines, mean anchor coverage 0.96, 9/18
fully anchored) with synced lyrics plus downloadable .srt per track. Documents
both player bugs and the headless-Chrome numeric probe that finally caught them.

public/subs/paper-airplane-in-september.srt

@@ -0,0 +1,71 @@
+1
+00:00:10,420 --> 00:00:15,099
+Sunlight on the wooden desk is moving inch by inch
+
+2
+00:00:15,099 --> 00:00:20,399
+Sparrows on the telegraph wire never seem to flinch
+
+3
+00:00:20,880 --> 00:00:25,600
+I fold a page of notebook paper creases nice and neat
+
+4
+00:00:25,600 --> 00:00:30,879
+And throw it out the window to the quiet autumn street
+
+5
+00:00:30,879 --> 00:00:36,359
+Fly away, paper plane, into the golden air
+
+6
+00:00:36,359 --> 00:00:41,640
+Carry all the little words I didn't dare to share
+
+7
+00:00:41,640 --> 00:00:48,719
+Goodbye to the summer clouds, hello to the breeze
+
+8
+00:00:48,719 --> 00:00:53,600
+Floating past the bicycles and underneath the trees
+
+9
+00:01:03,299 --> 00:01:08,379
+Chalk dust on the blackboard fades as afternoon goes by
+
+10
+00:01:08,379 --> 00:01:13,760
+Clouds like cotton candy drift across the September sky
+
+11
+00:01:13,760 --> 00:01:18,900
+Every simple little thing we took for granted then
+
+12
+00:01:18,900 --> 00:01:24,299
+Stays inside a photograph we'll look at once again
+
+13
+00:01:24,299 --> 00:01:29,659
+Fly away, paper plane, into the golden air
+
+14
+00:01:29,659 --> 00:01:34,900
+Carry all the little words I didn't dare to share
+
+15
+00:01:34,900 --> 00:01:41,680
+Goodbye to the summer clouds, hello to the breeze
+
+16
+00:01:41,680 --> 00:01:46,939
+Floating past the bicycles and underneath the trees
+
+17
+00:01:57,780 --> 00:02:02,000
+Underneath the autumn trees...
+
+18
+00:02:02,180 --> 00:02:06,219
+Goodbye, summer days.