port: three live-but-undocumented flags, and a dead instruction I wrote while fixing them

Their newest class -- the instruction is dead AND the working one is undocumented
-- inverts last iteration's sweep. I checked documented->parsed; the reverse is
parsed->documented, and it enumerates, so it completes rather than samples.

Eighteen flags parsed, fifteen documented, three live and undocumented:
--film-interval and --skip-at (used by verify-dwell, in no usage example) and
--no-hold, which plays a screen past its rest instead of clamping each element at
its hold, documented in DECISIONS.md and absent from the header a reader consults.
A capability that exists only in an 11000-line record does not exist to anyone
reading the interface.

Then I documented it wrong in the same command. I wrote the example as
--screen=title --no-hold --time=6 and tested it: the renders are byte-identical
because --time sets frozen and pose_at tests 'holding and not frozen', so an
explicit instant makes --no-hold inert. Without --time the pair differs by max
253. I wrote a dead instruction inside the commit fixing dead instructions, and it
only failed to ship because I ran the example rather than trusting that a parsed
flag works -- the gap I had named one iteration earlier.

Strongest evidence yet for their ranking: a wrong description costs a reader's
belief, a wrong instruction hands them a null result that looks like a finding.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01N7FiFFFwbvG2uxdcEh8HyF

docs/port/DECISIONS.md

@@ -9,7 +9,7 @@ dies, which is what this file is for.
 
 <!-- INDEX: generated by tools/port/index-decisions -- do not hand-edit -->
 
-213 sections. Search this before re-deriving anything.
+214 sections. Search this before re-deriving anything.
 
 * [P0 — the exporter, 2026-08-28](#p0--the-exporter-2026-08-28)
 * [P1 — Godot draws the screen, 2026-08-28](#p1--godot-draws-the-screen-2026-08-28)
@@ -224,6 +224,7 @@ dies, which is what this file is for.
 * [The grep found two more — and the reason is my correction *habit*, not my attention](#the-grep-found-two-more--and-the-reason-is-my-correction-habit-not-my-attention)
 * [Auditing headings — and my own index was amplifying the withdrawn ones](#auditing-headings--and-my-own-index-was-amplifying-the-withdrawn-ones)
 * [Ranking instructions above descriptions — swept, and the worst class is clean](#ranking-instructions-above-descriptions--swept-and-the-worst-class-is-clean)
+* [Live-but-undocumented flags — and I wrote a dead instruction while fixing dead instructions](#live-but-undocumented-flags--and-i-wrote-a-dead-instruction-while-fixing-dead-instructions)
 
 <!-- /INDEX -->
 ## P0 — the exporter, 2026-08-28
@@ -11274,3 +11275,40 @@ while real — are the cheap kind.
 examples end to end. I did not run all thirteen documented invocations. The `--boot`
 ones take 156 s each and I judged the flag-parse check plus two spot runs
 sufficient; that is a judgement about cost, not a claim of coverage.
+
+## Live-but-undocumented flags — and I wrote a dead instruction while fixing dead instructions
+
+Their newest class is one step past a stale instruction: **the instruction is dead
+*and* the working one is undocumented.** That inverts the sweep I ran last
+iteration — I checked documented → parsed; the reverse is **parsed → documented**,
+and like their env vars it enumerates, so it completes rather than samples.
+
+Eighteen flags parsed, fifteen documented, **three live and undocumented**:
+
+| flag | |
+|---|---|
+| `--film-interval` | used by `verify-dwell`, in no usage example |
+| `--skip-at` | same |
+| **`--no-hold`** | plays a screen **past its rest** instead of clamping each element at its hold — documented in `DECISIONS.md` and **absent from the header a reader consults** |
+
+📌 `--no-hold` is the one that matters: **a capability that exists only in an
+11 000-line record is, to anyone reading the interface, a capability that does not
+exist.**
+
+### 🔴 And then I documented it wrong, in the same command
+
+I wrote the example as `--screen=title --no-hold --time=6` and tested it. **The
+two renders are byte-identical — the flag no-ops.** `--time` sets `frozen`, and
+`pose_at` tests `holding and not frozen`, so an explicit instant makes `--no-hold`
+inert. Without `--time` the same pair differs by **max 253**.
+
+**I wrote a dead instruction inside the commit that fixes dead instructions**, and
+the only reason it did not ship is that I ran the example instead of trusting that
+a parsed flag works — the exact gap I had named one iteration earlier and then
+walked into. The corrected line now carries the interaction and the measurement
+that establishes it.
+
+⚠️ This is the strongest evidence yet for their ranking. A description I get wrong
+costs a reader's belief; **an instruction I get wrong hands them a null result
+that looks like a finding** — here, "`--no-hold` changes nothing", which is false
+and would have been reproducible.

port/scripts/boot.gd

@@ -7,6 +7,24 @@
 #   godot --path port -- --screen=main_menu
 #   godot --path port -- --screen=main_menu --capture=/tmp/godot.png
 #   godot --path port -- --screen=main_menu --time=0.5 --capture=/tmp/at-half.png
+#   godot --path port -- --screen=title --no-hold
+#                                    # play PAST the rest instead of clamping
+#                                    # each element at its own hold.
+#                                    # ⚠️ NOT with `--time`: that sets `frozen`,
+#                                    # and `pose_at` tests `holding and not
+#                                    # frozen`, so an explicit instant makes
+#                                    # `--no-hold` a no-op. Verified: identical
+#                                    # renders with `--time`, max 253 different
+#                                    # without it.
+#   godot --path port -- --boot --film=/tmp/b --film-interval=0.1
+#                                    # frame cadence for --film (default 0.25)
+#   godot --path port -- --boot --skip-at=1  # press (A) at 1 s to skip a movie
+#
+# 🔴 THESE THREE WERE LIVE AND UNDOCUMENTED. `--no-hold` is documented in
+# DECISIONS.md and was absent from the block a reader actually consults;
+# `--film-interval` and `--skip-at` are used by `tools/port/verify-dwell` and
+# appeared nowhere else. A capability that exists only in the record is, to
+# anyone reading the interface, a capability that does not exist.
 #   godot --path port -- --screen=main_menu --pose=rest --capture=/tmp/rest.png
 #   godot --path port -- --screen=title --overlay=press_start --time=4
 #   godot --path port -- --boot                      # the whole boot sequence