docs: richer report — data figures, success/failure frames, commit-pinned repo links

- experiment_charts.py generates 4 figures from experiments/ artifacts:
  held-out per-film F1, 16-combo ranking, DE search landscape, and the
  Downton detector-vs-tracker ghost timeline (replaces the blank
  title-card screenshot)
- new frames: 19-correct wedding shot (success case), Many Saints
  ghost-vs-unknown frame (three error classes in one image)
- rename rep4-optimizer-results.md -> model-bakeoff.md; rep4 kept only
  as the on-disk artifact prefix, explained once
- repo file references are now links via https://REPOLINK/<path>
  placeholders; build_site.sh pins them to the HEAD commit's raw URLs
  and fails the build if a linked path doesn't exist at HEAD
- drop references to removed scripts (scene_score.py, score_config.py)
  and to session-memory names; mark artifact-registry paths with their
  pull commands
- commit readme_example.jpg + pipeline_topology.svg so README renders
  on the plain Gitea repo view
- deploy_pages.sh: push built site/ to the gitea-pages branch

scripts/docs/deploy_pages.sh

@@ -0,0 +1,43 @@
+#!/bin/bash
+# deploy_pages.sh — push the built site/ to an orphan gitea-pages branch,
+# matching the convention Gitea Pages serves from
+# (pages.tourolle.paris/<owner>/<repo>/). Run scripts/docs/build_site.sh first.
+#
+# Uses a separate worktree so the main working tree / branch is untouched.
+set -euo pipefail
+
+REPO_ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/../.." && pwd)"
+cd "$REPO_ROOT"
+
+if [ ! -d site ]; then
+    echo "error: site/ not found — run scripts/docs/build_site.sh first" >&2
+    exit 1
+fi
+
+WORKTREE="$(mktemp -d)"
+trap 'rm -rf "$WORKTREE"' EXIT
+
+if git show-ref --verify --quiet refs/remotes/origin/gitea-pages; then
+    git worktree add -B gitea-pages "$WORKTREE" origin/gitea-pages
+else
+    git worktree add --orphan -B gitea-pages "$WORKTREE"
+fi
+
+# Replace the worktree's contents with the freshly built site.
+find "$WORKTREE" -mindepth 1 -maxdepth 1 -not -name '.git' -exec rm -rf {} +
+cp -r site/. "$WORKTREE/"
+touch "$WORKTREE/.nojekyll"
+
+cd "$WORKTREE"
+git add -A
+if git diff --cached --quiet; then
+    echo "No changes to deploy (site is identical to the current gitea-pages branch)."
+else
+    git commit -m "docs: deploy from $(git -C "$REPO_ROOT" rev-parse --short HEAD)"
+    git push origin gitea-pages:gitea-pages
+    echo "Deployed. Should be live shortly at:"
+    echo "  https://pages.tourolle.paris/dtourolle/scene-actor-extraction/"
+fi
+
+cd "$REPO_ROOT"
+git worktree remove "$WORKTREE" --force 2>/dev/null || true