docs: revise design + roadmap for single pano projector

Operator decision (2026-06-04): single panoramic projector spanning the
three walls showing the real selected video (nature-video focus), replacing
four projectors + a procedural side-wall renderer.

- Design spec: revision banner; updated §1, §6 (one pano projector), §7
  (procedural side walls REMOVED), §10 layout, §12 open questions.
- ROADMAP: sub-project 5 marked Dropped; diagram + dependency order updated;
  §3 player drives one pano output; cross-cutting decisions reconciled.
- Sub-project-2 spec: follow-up note updated to past tense (design spec done).

dominant_color's only consumer was the side walls, so it stays optional/opt-in
in the sub-project-2 tooling (already specced).

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

docs/ROADMAP.md

@@ -17,10 +17,12 @@ Design reference: [`specs/2026-06-04-human-experience-filter-design.md`](./super
 | 2 | Ingest & Tagging / Review tools | ⏳ Next        | a real library |
 | 3 | Player Runtime (Pi)             | ◻ Not started | the room runs |
 | 4 | Arduino Firmware (control panel)| ◻ Not started | real knobs |
-| 5 | Procedural Side Walls           | ◻ Not started | full immersion |
+| 5 | ~~Procedural Side Walls~~       | ❌ Dropped     | — (superseded) |
 
 **Dependency order:** 1 → 2, and 1 → 3. Sub-projects 3 and 4 share a serial
-protocol contract and can then proceed in parallel. 5 depends on 3.
+protocol contract and can then proceed in parallel. Sub-project 5 was **dropped**
+(2026-06-04): the move to a single panoramic projector showing real video across
+the three walls removes the procedural side walls — see the design spec §6/§7.
 
 ```
         ┌─────────────────────────┐
@@ -29,15 +31,17 @@ protocol contract and can then proceed in parallel. 5 depends on 3.
                     │
         ┌───────────┴───────────┐
         ▼                       ▼
-┌───────────────┐      ┌─────────────────┐
-│ 2. Ingest /   │      │ 3. Player        │
-│    Review     │─────▶│    Runtime (Pi)  │
-└───────────────┘ feeds└───┬─────────┬────┘
-   (fills catalog)         │         │
-                  serial   ▼         ▼ mood+color
-              ┌────────────────┐ ┌──────────────────┐
-              │ 4. Firmware    │ │ 5. Side Walls    │
-              └────────────────┘ └──────────────────┘
+┌───────────────┐      ┌─────────────────────┐
+│ 2. Ingest /   │      │ 3. Player Runtime   │
+│    Review     │─────▶│    (Pi) → 1 pano     │
+└───────────────┘ feeds│    projector         │
+   (fills catalog)      └──────────┬──────────┘
+                          serial   ▼
+                       ┌────────────────┐
+                       │ 4. Firmware    │
+                       └────────────────┘
+
+(5. Procedural Side Walls — dropped 2026-06-04, single pano projector)
 ```
 
 ---
@@ -91,7 +95,7 @@ files on the drive.
 ## 3. Player Runtime (Pi) ◻
 
 **Goal:** the thing that makes the room run — read the controls, pick media, play
-it on the primary wall.
+it across the single panoramic projector.
 
 **Delivers (`player/`):**
 
@@ -99,8 +103,8 @@ it on the primary wall.
 - Call `hef.selection.select()` on each change; loop the chosen 5–15 min segment
   until the knobs move; **crossfade** on change.
 - `None` mode → fade to black + silence.
-- Drive the **primary** projector; emit current `dominant_color` + dark/light to
-  the side-wall renderer (sub-project 5).
+- Drive the **single panoramic projector** spanning the three walls with the real
+  selected video (no primary/side split; no side-wall feed — sub-project 5 dropped).
 
 **Depends on:** sub-project 1 (`select`); a populated catalog from sub-project 2
 to be meaningful, but can be developed against a hand-authored catalog and a
@@ -134,20 +138,17 @@ a serial monitor) and the Pi player reacts.
 
 ---
 
-## 5. Procedural Side Walls ◻
+## 5. ~~Procedural Side Walls~~ ❌ Dropped (2026-06-04)
 
-**Goal:** make the mood axis physically felt in peripheral vision.
+**Superseded.** The move to a single panoramic projector showing the real selected
+video across the three walls (design spec §6/§7) removes the procedural ambient
+renderer entirely — the mood axis is felt through the chosen content itself. With
+it goes the only consumer of `dominant_color`, which becomes optional/opt-in in
+the ingest tooling (sub-project 2 spec §5.2).
 
-**Delivers (`sidewalls/`):**
-
-- Render a slow color wash on the three non-primary walls: **hue** from the
-  playing piece's `dominant_color`, **brightness** from the dark/light knobs.
-- Fade to black in `None` mode.
-
-**Depends on:** sub-project 3 emitting current `dominant_color` + mood state.
-**Done when:** given a color + mood input stream, the wash renders and tracks
-changes — testable headless by snapshotting rendered frames.
-**Open decisions:** runs on the primary Pi's extra outputs vs. a second Pi.
+> *Original goal (for the record): render a slow color wash on the three
+> non-primary walls — hue from the playing piece's `dominant_color`, brightness
+> from the dark/light knobs — to make the mood axis felt in peripheral vision.*
 
 ---
 
@@ -156,7 +157,10 @@ changes — testable headless by snapshotting rendered frames.
 Carried from the design spec's open-questions list — none block sub-project 2:
 
 - **Serial protocol framing** between Arduino and Pi (needed before 3 ⇄ 4).
-- **Player stack** on the Pi (mpv / ffmpeg / custom).
-- **Side walls** on the primary Pi vs. a second Pi.
+- **Player stack** on the Pi (mpv / ffmpeg / custom) and how the single panoramic
+  output is driven.
 - **`approved`-only enforcement** in the player.
-- **Media storage layout** on the drive (how `file_path` values are rooted).
+- ~~**Side walls** on the primary Pi vs. a second Pi~~ — resolved: side walls dropped.
+- ~~**Media storage layout** on the drive~~ — settled by the sub-project-2 spec
+  §6.3: media under a `media-root`, `file_path` stored relative to it; the player
+  joins it with its drive mount.