docs: fix drift — sync compose/volumes, studio coverage, mempalace link

Audit found README/AGENTS carried a stale compose/volume set that
diverged from the shipped docker-compose.yml (DOCKER_HUB + compose +
.env.example were already consistent — README was the outlier):

- README compose block + 'Volumes and persistence' table: correct volume
  names (devbox-shell-history not -bash-history; devbox-uv at
  ~/.local/share/uv not devbox-uv-tools at /opt/uv-tools — the latter
  would SHADOW the baked mempalace install at UV_TOOL_DIR); add
  devbox-ssh-local + devbox-zoxide; mark devbox-palace/-chroma-cache
  optional; WORKSPACE_PATH/SSH_KEY_PATH (not HOST_WORKSPACE).
- README quickstart: 'compose exec -u developer' (no USER in image; bare
  exec lands a root shell).
- README: pi-studio now 'shipped' not 'planned'; build-pipeline + tag
  table cover -studio + smoke-studio/build-variant-studio.
- AGENTS: backward-compat volume names corrected; repo-layout bullets
  cover pi-studio install + studio-expose + STUDIO_EXPOSE bridge.
- DOCKER_HUB: MemPalace source link -> upstream MemPalace/mempalace
  (matches Dockerfile.base + CHANGELOG refs).

Note: the shipped v1.0.0 CHANGELOG migration note still lists the old
(incorrect) volume names; left as immutable released history.

AGENTS.md

@@ -12,14 +12,17 @@ re-brand of opencode-devbox's `pi-only` variant.
   Node.js, Python toolchain, locales, ssh ControlMaster defaults, and
   `/etc/tmux.conf` with 0-indexed sessions.
 - `Dockerfile.variant` — `FROM base-<hash>`, adds pi + companions
-  (`pi-toolkit`, `pi-extensions`, `pi-fork`, `pi-observational-memory`).
+  (`pi-toolkit`, `pi-extensions`, `pi-fork`, `pi-observational-memory`)
+  and, when `INSTALL_STUDIO=true`, vendors `pi-studio` to `/opt/pi-studio`
+  (`-studio` variant).
 - `entrypoint.sh` — UID/GID alignment as root, then drops to `developer`.
 - `entrypoint-user.sh` — per-container start: SSH ControlMaster socket
   dir, LAN-access setup, MemPalace init, pi-toolkit + pi-extensions
-  deploy, mempalace-bridge symlink, fork/recall pi-install, skillset
+  deploy, mempalace-bridge symlink, fork/recall + pi-studio pi-install,
+  optional `studio-expose` bridge (when `STUDIO_EXPOSE=1`), skillset
   deploy.
 - `rootfs/` — files baked into the image (bash aliases, inputrc,
-  setup-lan-access.sh).
+  setup-lan-access.sh, `studio-expose` helper).
 - `scripts/smoke-test.sh` — sanity checks run by CI before pushing to Hub.
 - `.gitea/workflows/docker-publish.yml` — two-phase CI (base-decide →
   build-base → smoke → build-variant → promote-base-latest →
@@ -129,8 +132,9 @@ deprecated artifacts (to be removed in opencode-devbox v2.0.0).
 ## Backward compatibility
 
 - The host `~/.mempalace` bind-mount path is unchanged.
-- Volume names (`devbox-pi-config`, `devbox-bash-history`,
-  `devbox-nvim-data`, `devbox-uv-tools`, `devbox-chroma-cache`) are
+- Volume names (`devbox-pi-config`, `devbox-ssh-local`,
+  `devbox-shell-history`, `devbox-zoxide`, `devbox-nvim-data`,
+  `devbox-uv`; optional `devbox-palace`, `devbox-chroma-cache`) are
   unchanged.
 - `~/.pi/agent/` layout inside the container is unchanged; existing
   named volumes work without recreation.