Reorganize docs into category folders and drop the retired head-review page

Group the top-level docs into docs/project, docs/design, docs/assets and
docs/process, each with its own README index. Delete the superseded
docs/screens/head-review page and sheets. Rewrite every markdown link,
absolute docs path and tool/test reference to the new locations, fix the
pre-existing broken anchors and remove the dead Joke Shop photo-board link.
check_docs OK, Python tooling 167/167.

docs/screens/refs/README.md

@@ -76,8 +76,8 @@ committed here is the redacted copy, not the original.
 ## How the folder is used
 
 - Build the venue **three-up boards** (photo | concept | current capture) for the review verdicts.
-- Link the board from the venue map document (`docs/venues.md#hollywood-boulevard`,
-  `docs/venues.md#the-joke-shop`) and from the local-map block notes.
+- Link the board from the venue map document (`docs/design/venues.md#hollywood-boulevard`,
+  `docs/design/venues.md#the-joke-shop`) and from the local-map block notes.
 - Cite the sidecar when a texture, proportion or signage decision is derived from a photo.
 - Refresh the board when a venue change makes an old reference misleading, and note the change in
   the sidecar.

docs/screens/refs/SIDECAR-TEMPLATE.md

@@ -34,12 +34,12 @@ attribution string for CC BY / CC BY-SA in the `Author` or a note below.
 
 | Decision | Evidence | Where it landed |
 | --- | --- | --- |
-| e.g. six-column spacing kept at 2.4 m | photo 1, measured against door width | `docs/venues.md#hollywood-boulevard` |
+| e.g. six-column spacing kept at 2.4 m | photo 1, measured against door width | `docs/design/venues.md#hollywood-boulevard` |
 | e.g. banner red sampled to `#8a1f24` | photo 1 + photo 2 | `docs/screens/refs/hollywood/` notes, facade kit |
 
 ## Generated boards used with this set
 
-Generated frames live in [`../../concepts/`](../../concepts/README.md); reference them here so the
+Generated frames live in [`../../concepts/`](../concepts/README.md); reference them here so the
 three-up sheet is reproducible.
 
 | Board | Path | Model | Prompt / seed | Generated | Spend |

docs/screens/refs/hollywood/README.md

@@ -11,7 +11,7 @@ TV Studio board.
 
 Provenance, licences and the decisions these photos informed are in
 [`SIDECAR.md`](SIDECAR.md). The rules for this folder are in
-[`../README.md`](../README.md); generated art-direction frames live in
+[`../README.md`](README.md); generated art-direction frames live in
 [`../../concepts/hollywood_boulevard/`](../../concepts/hollywood_boulevard/README.md).
 
 | Photo | What it is evidence for |
@@ -35,5 +35,5 @@ Provenance, licences and the decisions these photos informed are in
 - The east retail neighbour beyond the temple (the modern retail block), for facade rhythm at the
   right-hand edge of the venue.
 
-Add new files with the naming convention in [`../README.md`](../README.md) and list them in the
+Add new files with the naming convention in [`../README.md`](README.md) and list them in the
 sidecar in the same commit.

docs/screens/refs/hollywood/SIDECAR.md

@@ -26,7 +26,7 @@
 Licence texts: [CC BY 2.0](https://creativecommons.org/licenses/by/2.0/),
 [CC BY 3.0](https://creativecommons.org/licenses/by/3.0/) and
 [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0/). The CC BY and CC BY-SA files are
-also listed in [`../../../CREDITS.md`](../../../CREDITS.md) under "Development-only reference
+also listed in [`../../../../CREDITS.md`](../../../../CREDITS.md) under "Development-only reference
 images".
 
 **CC BY-SA review (2026-11-03):** `hollywood-boulevard-night-context-ccbysa.jpg` is redistributed
@@ -51,10 +51,10 @@ before use.
 
 | Decision | Evidence | Where it landed |
 | --- | --- | --- |
-| Six Ionic columns, ~2.4 m spacing, 8 steps | facade photo measured against the door width | `docs/venues.md#hollywood-boulevard` geometry notes |
+| Six Ionic columns, ~2.4 m spacing, 8 steps | facade photo measured against the door width | `docs/design/venues.md#hollywood-boulevard` geometry notes |
 | Masonic parapet motto and medallions | 1922 elevation + facade photo | `WorldBuilder` facade, `docs/screenshots/01-venue-overview.png` |
 | Three vertical event banners | facade photo | facade banners and the day/night capture set |
-| Red carpet + barrier staging narrows the sidewalk | premiere photo | `docs/venues.md#hollywood-boulevard` event staging notes |
+| Red carpet + barrier staging narrows the sidewalk | premiere photo | `docs/design/venues.md#hollywood-boulevard` event staging notes |
 | Across-street height and plaza opening | Ovation photo | opposite frontage massing |
 | TV Studio arrival staging (bulb canopy, car, barriers) | premiere staging photo | `VENUE_SPECS["tv_studio"]` and the Late Night TV Studio venue docs |
 | Terrazzo band width, star size/spacing | terrazzo + star close-up photos | `WalkOfFame` band geometry and the paver material |