v2.1.0: symlink OMOS bundled skills from image, bump opencode 1.17.4->1.17.5

Deploy the five oh-my-opencode-slim bundled skills (clonedeps, codemap,
deepwork, oh-my-opencode-slim, simplify) by symlinking them from the image
path into ~/.agents/skills/ on every container start, instead of the
installer copying them into the persistent config volume on first run only.
Image-sourced links mean 'docker compose pull' + recreate refreshes the
skills with no installer run and no config reset; the old copy-on-first-run
froze them in the volume forever.

- entrypoint-user.sh: new non-fatal OMOS bundled-skills reconcile block
  (runs after skillset deploy so OMOS wins the simplify collision; absolute
  symlinks; gated by OMOS_SKILLS, now independent of ENABLE_OMOS). Both
  installer calls now pass --skills=no. One-time migration backs up (never
  deletes) frozen real copies in ~/.config/opencode/skills/ to .bak.<epoch>.
- scripts/smoke-test.sh: assert the bundled-skills source path on omos.
- Bump OPENCODE_VERSION 1.17.4 -> 1.17.5.
- Versioning: document the move to independent image semver (v2.0.0 was the
  decouple point), mirroring pi-devbox. README/AGENTS/.env.example/CHANGELOG
  updated; new docs/omos-skills.md.

CHANGELOG.md

@@ -8,6 +8,51 @@ Tags follow `v{opencode_version}[letter]` — bare tag for the first build on a
 
 ## Unreleased
 
+## v2.1.0 — 2026-06-13
+
+Image-semver **minor**: adds the OMOS bundled-skills image-symlink mechanism and
+bumps opencode. `v2.0.0` decoupled image versioning from the opencode version
+(see [AGENTS.md](AGENTS.md#versioning-scheme)); this is the first feature release
+on the semver line, mirroring how the sibling `pi-devbox` repo moved to semver
+after its own `v1.0.0` decouple.
+
+### Bumped: opencode-ai 1.17.4 → 1.17.5
+
+`OPENCODE_VERSION` ARG in `Dockerfile.variant`.
+
+### Changed: OMOS bundled skills are now symlinked from the image, not copied
+
+The five skills bundled with `oh-my-opencode-slim` (`clonedeps`, `codemap`,
+`deepwork`, `oh-my-opencode-slim`, `simplify`) are now **symlinked from the
+image** into `~/.agents/skills/` on every container start, instead of being
+**copied** into `~/.config/opencode/skills/` once on first run by the OMOS
+installer.
+
+Why: the old copy landed in the persistent `devbox-opencode-config` volume and
+was gated by config-existence, so it **froze** at whatever the image shipped on
+first run — pulling a newer image never refreshed the skills, and the only
+update path (`OMOS_RESET=true`) also clobbered the user's hand-tuned
+`opencode.jsonc`. With the symlink approach the link target lives in the image,
+so **`docker compose pull` + recreate updates the skills for free** — no
+installer run, no config reset.
+
+- `entrypoint-user.sh`: new OMOS bundled-skills reconcile block (runs after the
+  skillset deploy so OMOS wins the `simplify` name collision; absolute symlinks;
+  non-fatal; gated by `OMOS_SKILLS`, now independent of `ENABLE_OMOS` and the
+  presence of the bundled-skills source on the omos variant).
+- `entrypoint-user.sh`: both `oh-my-opencode-slim install` calls now pass
+  `--skills=no` — the installer manages only `oh-my-opencode-slim.json`.
+- One-time migration backs up (never deletes) any frozen real copies in
+  `~/.config/opencode/skills/` to `<name>.bak.<epoch>` (marker:
+  `~/.config/opencode/.omos-skills-migrated`).
+- `scripts/smoke-test.sh`: asserts the bundled-skills source path exists on the
+  omos variant (catches an upstream package restructure).
+- Docs: new `docs/omos-skills.md`; updated `README.md`, `AGENTS.md`,
+  `.env.example` (`OMOS_SKILLS` semantics).
+
+**Editing `entrypoint-user.sh` advances the base hash** — this release carries a
+full base rebuild and a `base-latest` re-promote.
+
 ## v2.0.0 — 2026-06-13
 
 **Major release: pi is fully removed from opencode-devbox** (deprecated in