research: Dütsch analyzer — explicit opt-in horizon, complete-cycle check, HF component report

Default (no --horizon) keeps the original cap-11 scoring. --horizon N
requires complete cycles 1..N in every case, passes the horizon to
common_window and labels the JSON. The unqualified phase-locked HF force
component is reported per case. Protocol section 6b declares the D40/60D
31-cycle duration-only diagnostic.

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

docs/validation/duetsch_re100_kc5_protocol.md

@@ -204,6 +204,25 @@ Superseded (earlier drafts): the velocity-jump start, guessed stations and
 phases, "C_M" for c_i, and the uncertainty wording; cycles 4–6, the 30-cycle
 cap and the earlier tolerance numbers.
 
+## 6b. Amendment: duration-only diagnostic (declared before the run)
+
+- Background: the D40 domain stage (20 D / 40 D / 60 D, 11.25 T each) failed
+  settling in every box (no window). That result stands.
+- One declared diagnostic: D = 40, 60 D box, from rest, through cycle 31
+  (157,500 steps = 31.25 T). Physics, settling tolerances, bands and
+  production unchanged; three proof pairs plus a continuously settled
+  K..K+2 with K ≤ 29.
+- Invocation: `run.py --D 40 --box 60 --cycles 31` then
+  `analyze.py --horizon 31`; the JSON records `horizon` and `horizon_mode`.
+  Without `--horizon` the analyzer is the original cap-11 scoring.
+- Failure at 31.25 T: report and stop; no automatic extension, matrix, D80
+  or VIV. A pass shows only that this box settles with time; it is not a
+  domain or literature pass.
+- The phase-locked high-frequency force component (residual of the mean
+  waveform after its Morison reconstruction, above 20/T) is reported per case
+  as unqualified; it needs separate qualification before any Morison or
+  literature statement.
+
 ## 6a. Driver unit tests (CPU, before any run)
 
 - Phase/cycle arithmetic: s ↔ (k, φ), cycle boundaries, bin membership,