docs: archive the July 2026 report; new methodology for the opencv5 run

The July report (4-model ArcFace/LVFace bake-off, pre-opencv5 framework,
3-film training + held-out validation) is superseded by the opencv5 build:
single-model LVFace-B, a 6-knob DE sweep over all 9 films, flood-fill
presence, and the registry/decode fixes. Rather than overwrite it, archive
it date-suffixed and start the current report fresh.

- Rename the six July result pages to *-2026-07.md, rewrite their
  intra-archive cross-links, and add an "Archived (July 2026)" banner to each.
- mkdocs nav: current report at top, the July set under an Archive section.
- New docs/methodology.md for the opencv5 run: corrects the withdrawn
  anneal_sec/extinction_sec presence bridging (windows are now
  [first_seen, last_seen], AR-012/013), documents the two presence modes
  (track_extent / flood), and records that every eval scores all 9 films.

The current experiment log (model-bakeoff.md) and Home rewrite land once
the DE sweep converges and the final optimum is known.

docs/methodology.md

@@ -1,11 +1,9 @@
 # How we score against X-Ray
 
-Every number in this report, every F1 and misID count, comes from one
-comparison. The comparison has a mismatch at its core that shapes nearly
-every finding in this report: the ground truth is scene-level, the
-pipeline's output is per-second, and the two do not mean the same thing.
-This page documents that comparison once, so the findings pages can rely on
-it without re-explaining it.
+Every number in this report comes from one comparison, and that comparison
+has a mismatch at its core: the ground truth is scene-level, the pipeline's
+output is per-second, and the two do not mean the same thing. This page
+documents the comparison once so the findings can rely on it.
 
 ## What Amazon X-Ray records
 
@@ -13,12 +11,12 @@ X-Ray ships three tables per film: `scenes.csv` (a list of `[start, end]`
 timespans), `people_in_scenes.csv` (which actors are credited in each
 scene), and `people.csv` (actor identities). There is no per-frame or
 per-second annotation anywhere in X-Ray. A scene might run 45 seconds, and
-X-Ray records one cast list for the entire span, not "on screen from
-second 12 to second 30."
+X-Ray records one cast list for the entire span, not "on screen from second
+12 to second 30."
 
-To compare this against per-second predictions, `second_score.py` expands
-every scene into per-second ground truth by copying the whole scene's cast
-list onto every second inside it:
+To compare against per-second predictions, `second_score.py` expands every
+scene into per-second ground truth by copying the whole scene's cast list
+onto every second inside it:
 
 ```python
 for sn, (t0, t1) in spans.items():
@@ -27,48 +25,46 @@ for sn, (t0, t1) in spans.items():
         timeline[t] = cast
 ```
 
-That is the entire mechanism. If X-Ray credits five actors to a 30-second
-scene, all five count as ground truth present for all 30 seconds, including
-seconds where only one of them is on screen. This is not a simplification
-introduced by the pipeline; it is the only reading of X-Ray's data that is
-possible, because X-Ray itself does not record anything finer-grained.
+If X-Ray credits five actors to a 30-second scene, all five count as ground
+truth present for all 30 seconds, including seconds where only one is on
+screen. This is not a simplification the pipeline introduces; it is the only
+reading X-Ray's data supports, because X-Ray records nothing finer.
 
-## Why an offscreen name can be scored correct
+## How the pipeline reports presence
 
-A name listed under Offscreen with a correct (green) label is not the
-pipeline guessing or padding its score. It is the pipeline correctly
-answering the question X-Ray actually asks: is this actor part of this
-scene. It answers that question using a presence window (`[start, end]`,
-held open across cuts by `anneal_sec` and `extinction_sec`), which matches
-X-Ray's scene-level semantics more closely than a raw per-frame detection
-would.
+A presence claim is one actor owning one time window. How that window is
+derived is a tunable choice — a knob the optimizer weighs — with two modes:
 
-A system that only reported "this actor is visible in this exact frame"
-would score worse against X-Ray's scene-level ground truth, producing a
-false negative every time the camera cuts away from a character who is
-still present in the scene. Not because it is wrong about the world, but
-because it would be answering a stricter, different question than the one
-X-Ray's data supports. The presence-window design exists specifically to
-answer X-Ray's actual question.
+- **`track_extent` (default).** A claim is exactly `[first_seen, last_seen]`
+  of a track the actor owned (AR-012), ending at the last sighting and never
+  after (AR-013). There is no keep-alive: the withdrawn `anneal_sec` and the
+  scene-tracker `extinction_sec` — which the July report's windows were held
+  open by — are **gone**. A track that survives its own gaps needs no bridge;
+  a gap after the final sighting is never claimed.
+- **`flood`.** Each claim is snapped to the shot it sits in, so an actor seen
+  once anywhere in a shot is reported for the whole shot
+  `[prev_boundary, next_boundary]`. Boundaries come from TransNetV2 shot
+  detection when available, otherwise from the always-on histogram cut
+  detector (`is_cut`). This trades precision for recall against X-Ray's
+  scene-level granularity, and the optimizer decides per run whether it pays.
 
-## What this resolves and what it does not
+Do not confuse the surviving `track_extinction_sec` with the withdrawn
+scene `extinction_sec`: the former bounds how long a lost track stays
+available for **re-association** (a tracking question), and never extends a
+presence claim.
 
-This resolves the semantic mismatch between a scene and an instant. It does
-not resolve two other limitations, both discussed in the
-[LVFace deep dive](lvface-deep-dive.md).
+## The two limits this does not resolve
 
 **The face-vs-presence ceiling.** X-Ray credits scene membership regardless
 of whether a face is ever visible: background crew, characters shot from
-behind, voice-only presence. No amount of bridging recovers a face that
-never appears on screen. This is a hard ceiling on recall, not a defect.
+behind, voice-only presence. No face pipeline can recover a face that never
+appears, so recall against X-Ray is a structural ceiling, not a defect.
 
-**Extinction bridging can overshoot.** The same presence-window mechanism
-that correctly answers "still in this scene" during a normal cut can also
-bridge across a scene boundary it has no way to detect. A hard cut into a
-different scene with no faces, such as closing credits, carries the
-previous scene's identities forward until the window expires. This is the
-mechanism behind Downton Abbey's recall collapse, documented in the deep
-dive.
+**Flood-fill can overshoot.** Snapping to a shot correctly answers "still in
+this scene" through an intra-scene cut, but a shot boundary is not a scene
+boundary: on a film with sparse cuts, flood-fill can carry an actor across a
+long "shot" they only briefly appeared in. This is why flood-fill is a knob,
+not a default — its value depends on the film's cut density.
 
 ## Precision, recall, and the misID weighting
 
@@ -77,49 +73,46 @@ Per sampled second `t`:
 **TPI** (true positive instances): actors both X-Ray and the pipeline agree
 are present.
 
-**FPI** (false positive instances): actors the pipeline reports that are
-not in X-Ray's cast for this second. Split into two categories:
+**FPI** (false positive instances): actors the pipeline reports that are not
+in X-Ray's cast for this second, split into:
 
-- **FPI_incast**: the actor is in the film's cast, just not credited to
-  this particular scene. A timing or boundary slip.
+- **FPI_incast**: the actor is in the film's cast, just not credited to this
+  scene. A timing or boundary slip.
 - **FPI_misid**: the actor is not in the film's cast at all. A genuine
-  wrong-identity error, weighted 10x in the precision objective, because
-  naming someone who is not even in the film is a categorically worse
-  error than a few seconds of scene-boundary slop.
+  wrong-identity error, weighted **10×** in the precision objective, because
+  naming someone not even in the film is categorically worse than a few
+  seconds of scene-boundary slop.
 
 !!! note "Every headline `P` and `F1` is misID-weighted"
 
-    The precision reported throughout this report, and therefore the F1
-    derived from it, puts each `FPI_misid` into the denominator **10 times**
+    Precision puts each `FPI_misid` into the denominator 10 times
     (`precision = TPI / (TPI + FPI_incast + 10·FPI_misid)`,
     [`second_score.py`](https://REPOLINK/scripts/optimizer/second_score.py)).
-    This is deliberate: the whole point is to punish naming an out-of-film
-    actor far harder than a scene-boundary slip. But it means the `P` column
-    is not raw precision, and a misID-heavy film's `P` is depressed
-    super-linearly. `second_score.py` also emits an unweighted `precision_raw`
-    (always ≥ the weighted `P`); where the gap matters, The Many Saints of
-    Newark, weighted `P` 54.7% vs. raw 78.4%, the [LVFace deep dive](lvface-deep-dive.md)
-    reports both. When comparing `P` across films, remember you are comparing a
-    quantity that penalizes misIDs, not just a hit rate.
+    This deliberately punishes naming an out-of-film actor far harder than a
+    boundary slip, so the `P` column is not raw precision and a misID-heavy
+    film's `P` is depressed super-linearly.
 
-**FN** (false negatives): actors X-Ray lists that the pipeline never
-reports, counted only for actors who have a gallery reference embedding.
-Across the 9-film benchmark, coverage of X-Ray's credited cast ranges from
-20% to 79% by film (see
-[the full experiment log](model-bakeoff.md#gallery-coverage-per-film)); an
-actor with no reference photo can never be recognized regardless of model
-quality, and counting them as a miss would penalize gallery coverage, not
-recognition accuracy.
+**FN** (false negatives): actors X-Ray lists that the pipeline never reports,
+counted **only** for actors who have a gallery reference embedding. An actor
+with no reference photo can never be recognized, and counting them as a miss
+would measure gallery coverage, not recognition accuracy.
 
-Two further numbers are reported alongside F1:
+Two further numbers accompany F1:
 
 **agreement_rate**: mean per-second Jaccard overlap
-(`|Pred ∩ GT| / |Pred ∪ GT|`), partial credit. Naming 2 of 3 present actors
-scores 2/3, not 0.
+(`|Pred ∩ GT| / |Pred ∪ GT|`) — partial credit, so naming 2 of 3 present
+actors scores 2/3, not 0.
 
-**exact_match_rate**: the fraction of sampled seconds where the pipeline's
-named set exactly equals X-Ray's, no partial credit. Far harsher, and
-dominated by recall, since any single missed actor zeroes that second.
+**exact_match_rate**: the fraction of seconds where the pipeline's named set
+exactly equals X-Ray's — no partial credit, dominated by recall.
+
+## The benchmark set
+
+Unlike the July report — which trained on a 3-film subset and validated on
+held-out films to keep evaluations fast — this run scores **all 9 films on
+every evaluation**. The registry one-clock fix and uncapped dumps made
+full-set replay affordable, so the reported optimum is tuned against the
+complete set rather than a training subset.
 
 ## Reproduce
 
@@ -129,6 +122,5 @@ python3 scripts/optimizer/second_score.py \
     --gallery experiments/galleries/gallery_LVFace-B_Glint360K.h5
 ```
 
-See also [the full experiment log](model-bakeoff.md) for how `pred.json` is
-produced, and the [LVFace deep dive](lvface-deep-dive.md) for what these
-mechanisms look like frame by frame.
+See the [full experiment log](model-bakeoff.md) for how `pred.json` is
+produced and where the shipped `src/config.hpp` defaults come from.