docs(frank-tts): retire the 5.5 s cold-voice claim everywhere it still lived

PR #15 corrected the engine's page, the research brief's law bullet and the
warmer's header, but the retired ladder had six more homes: both quadlet files
("6.2-8.0 s… 0.5 ms", "~6-8 s each", "paying the 5.5 s cold decode"),
`scripts/frank-tts-engine.env` (the whole law paragraph and the WARM_TEXT note),
`scripts/frank-tts.env`, the [[Frank TTS]] troubleshooting row that told an
operator to expect ~5.5 s, the research brief's consequences paragraph, and one
test comment.

All re-keyed to what was measured on the deployed container 2026-10-18: the
first synthesis of a freshly registered voice costs 1,883 ms against 1,226-1,283
ms afterwards, so the warm pass buys about 0.6 s — and the reason it exists at
all, which the pages never led with, is that the registry is memory-only: without
the hook every voice name is a 400 until somebody synthesizes. The trial's dated
worklog entry stays as written; the correction points at it.

No behavior change: comments, unit lore and docs only, so no cfhash move and no
image rebuild.

scripts/frank-tts-engine.env

@@ -27,18 +27,17 @@
 # below stop describing the process you are running. Nothing in this fleet
 # pins this container; that is a decision, not an oversight.
 #
-# THE COLD-VOICE LAW (why the unit has an ExecStartPost at all). The first
-# speech request for a registered voice decodes the ENTIRE reference clip to
-# snapshot its codec state: 6.2-8.0 s total, first audio byte at 5,530 ms. Every
-# later request for that voice restores the snapshot in 0.5 ms. Registrations
-# live in memory only, so a restart loses them and re-registration alone does
-# NOT warm the voice — the warm pass has to synthesize something. So
-# dankclaw/voiceservice/tts-engine-warm.sh (in the image at
-# /app/warm-voices.sh) runs on every start and speaks one short sentence per
-# voice. Skip it and the first person to ask for audio that day waits 5.5 s in
-# silence. It runs INSIDE this container — `podman exec`, from the unit's
-# ExecStartPost — so it reads /voices here and the keys at the bottom of this
-# file are its knobs too.
+# THE REGISTRY LAW (why the unit has an ExecStartPost at all). Registrations live
+# in memory only, so a restart loses them, and re-registration alone does NOT warm
+# a voice — the warm pass has to synthesize something. Without it the façade
+# answers 400 for every name until somebody asks for audio. So
+# dankclaw/voiceservice/tts-engine-warm.sh (in the image at /app/warm-voices.sh)
+# runs on every start and speaks a short sentence twice per voice. The penalty it
+# removes is about 0.6 s, NOT the trial's 6.2-8.0 s: measured on the built
+# container 2026-10-18 against an empty registry, the first synthesis cost
+# 1,883 ms and the requests after it 1,226-1,283 ms. The hook runs INSIDE this
+# container — `podman exec`, from the unit's ExecStartPost — so it reads /voices
+# here and the keys at the bottom of this file are its knobs too.
 #
 # STREAMING IS NOT BUFFERED. The same seed gives audio that differs in 92.2 %
 # of samples (-41.6 dB RMS) between `response_format=pcm` (the streaming path,
@@ -125,8 +124,8 @@ HEALTH_WAIT=300
 # The sentence each voice speaks to snapshot its codec state, and the text the
 # second (warm-timing) pass repeats. Fixed on purpose: the cold=/warm= numbers in
 # the journal are comparable across boots only if the input is the same. Kept
-# short because warming a library is serial — one cold decode per voice, 6-8 s
-# each, inside the unit's start deadline.
+# short because warming a library is serial — two syntheses per voice, ~5 s each,
+# inside the unit's start deadline.
 # QUOTED, and the quoting means two different things to the two readers of this
 # file, which is the trap here:
 #   * bash (`set -a; source`, how the repo's seams and any human read it) needs

scripts/frank-tts.env

@@ -35,8 +35,9 @@
 #                  shim resolves the voice and re-encodes to mp3 when asked. The
 #                  shipped engine (frank-tts-engine) speaks a voice it has
 #                  REGISTERED on itself, from the same /home/dank/voices packs,
-#                  and warms them at boot — see [[Frank TTS Engine]] for why an
-#                  unwarmed voice costs the first caller 5.5 s.
+#                  and warms them at boot — see [[Frank TTS Engine]] for what that
+#                  boot warm is for (a memory-only registry: without it every name
+#                  is a 400) and what it saves (~0.6 s).
 #   llama-tts-cli  run LLAMA_TTS_BIN once per request with
 #                  --tts-speaker-file <reference.wav>, nice 19 so a narration
 #                  never starves the text endpoints on this box. Needs