content(sim): rotating clip pools + progressive tracked labels & emotions

Content-pipeline Increment 2, part 1 (the experience). Implements design §11
(docs/superpowers/specs/2026-06-24-content-pipeline-design.md):

- Rotating pool (§11.1): each ring scale references a POOL of vetted clips
  (docs/content-candidate-pool.md); the player picks a random member on landing.
  player.ring.Scale gains `pool` + pure `pick_clip_id(scale, r)` (injected
  randomness); the pick happens at the API boundary (random.random()), a delta=0
  advance is the initial/re-roll pick. clips.py parses/exposes the pool; the
  client lands on move.target_clip_id. Back-compat: a scale with only clip_id is
  a pool of one.
- Rename ring scale forest -> coast (new land<->sea scale, orbit..reef); ring
  order cosmos -> orbit -> coast -> reef -> abyss -> wrap. Cleanup: dropped the
  leftover local media (cosmos_traverse, orbit_westcoast, old forest/reef, the
  Increment-1 orbit/abyss single bases); new coast-edge transition placeholders.
- Time-windowed tracked labels (§11.2): annotations gain appear/disappear
  (loop-normalized, wraps across the seam); a label shows only while on screen
  and its box tracks the subject. abyss + reef pools authored as test material.
- Progressive LEFT detail tiers (§11.3): per-object `salience` (first shows at
  Left 5-salience) + tiered strings (general -> specific -> scientific -> +fact)
  escalating with the Left knob; replaces flat min_level gating. Strings may be a
  tier list or a static string (back-compat). No engine change (client reads
  overlay.level).
- Progressive RIGHT emotion tiers (§11.4): affect vocabulary escalates basic ->
  compound with the Right knob (dream.strength); appearance still gated by
  min(left,right). No engine change.

New simulator/build_pool_manifest.py holds the hand-authored content and emits
the 19-clip pool manifest (the reproducible baseline). setup_scales_media.py
marked superseded. 251 passed / 4 skipped (+ ring pool + API pool/window tests).
By-eye visual review deferred to the operator (no Chrome on this box).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

simulator/clips.py

@@ -73,6 +73,18 @@ def load_manifest(path: str | Path) -> list[Clip]:
     return [_clip_from_dict(c) for c in data["clips"]]
 
 
+def _scale_from_dict(s: dict[str, Any]) -> Scale:
+    """A ring scale node, with its rotating clip pool (content-pipeline §11.1).
+
+    Accepts a `pool` list (the rotating model) and/or a legacy single `clip_id`.
+    The primary `clip_id` is the explicit one if given, else the first pool
+    member; `pool` defaults to `(clip_id,)` for a pre-pool manifest.
+    """
+    pool = tuple(s.get("pool", []))
+    clip_id = s.get("clip_id") or (pool[0] if pool else "")
+    return Scale(id=s["id"], clip_id=clip_id, pool=pool)
+
+
 def load_ring(path: str | Path) -> ScaleRing | None:
     """Load the optional `ring` section as a `ScaleRing`, or None if absent.
 
@@ -85,9 +97,7 @@ def load_ring(path: str | Path) -> ScaleRing | None:
     ring = data.get("ring")
     if not ring:
         return None
-    scales = tuple(
-        Scale(id=s["id"], clip_id=s["clip_id"]) for s in ring.get("scales", [])
-    )
+    scales = tuple(_scale_from_dict(s) for s in ring.get("scales", []))
     transitions = tuple(
         Transition(file=t["file"], model=t.get("model", ""))
         for t in ring.get("transitions", [])
@@ -97,27 +107,46 @@ def load_ring(path: str | Path) -> ScaleRing | None:
 
 def ring_to_dict(ring: ScaleRing, clips: list[Clip]) -> dict:
     """JSON form of the ring for the API: ordered scales (with their clip title)
-    and the per-edge transitions."""
+    and the per-edge transitions.
+
+    Each scale carries its full rotating `pool` (clip id + title per member) plus
+    the primary `clip_id`/`title` for back-compat. The client lands on a member
+    chosen at the API boundary (`/api/ring/advance` → `target_clip_id`)."""
     titles = {c.id: c.title for c in clips}
     return {
         "scales": [
-            {"id": s.id, "clip_id": s.clip_id, "title": titles.get(s.clip_id, s.id)}
+            {
+                "id": s.id,
+                "clip_id": s.clip_id,
+                "title": titles.get(s.clip_id, s.id),
+                "pool": [
+                    {"clip_id": cid, "title": titles.get(cid, cid)}
+                    for cid in s.members
+                ],
+            }
             for s in ring.scales
         ],
         "transitions": [{"file": t.file, "model": t.model} for t in ring.transitions],
     }
 
 
-def ring_move_to_dict(move: RingMove, ring: ScaleRing) -> dict:
+def ring_move_to_dict(
+    move: RingMove, ring: ScaleRing, chosen_clip_id: str | None = None
+) -> dict:
     """JSON form of an encoder move: the landing scale's clip and the ordered
     transition clips to play (with direction). `fast` flags a collapsed fast-spin
-    pass; the single step then carries `blended` so the renderer plays it quick."""
+    pass; the single step then carries `blended` so the renderer plays it quick.
+
+    `target_clip_id` is the pool member the player should load on landing. The
+    caller passes the random pick (`pick_clip_id(landed_scale, random.random())`,
+    content-pipeline §11.1); when omitted it falls back to the scale's primary
+    `clip_id` (deterministic — keeps pre-pool callers/tests working)."""
     return {
         "from_index": move.from_index,
         "to_index": move.to_index,
         "wrapped": move.wrapped,
         "fast": move.fast,
-        "target_clip_id": scale_at(ring, move.to_index).clip_id,
+        "target_clip_id": chosen_clip_id or scale_at(ring, move.to_index).clip_id,
         "steps": [
             {
                 "edge": st.edge,