chore(guides): update 3 guide(s)

apps/docs/content/guides/choose-runtime-base.mdx

@@ -3,7 +3,9 @@ title: "Choosing a Runtime Base on Zerops"
 description: "**Use Alpine** as the default base for all services. Use Ubuntu only when you need system packages not available in Alpine. Use Docker only for pre-built images."
 ---
 
-**Use Alpine** as the default base for all services. Switch to Ubuntu only for **glibc** needs (musl incompatibility): CGO-enabled Go, glibc-built Python/C-extension wheels, or the **Deno** runtime (no Alpine build). Needing a package is NOT itself a reason — both bases install packages (`sudo apk add` / `sudo apt-get install`). Use Docker only for pre-built images.
+The OS is part of the base identifier, never a separate field: `alpine/<tech>@<ver>` or `ubuntu/<tech>@<ver>` — the same value in the import `type` and in both `build.base` and `run.base` of zerops.yaml. Always write the prefix: a bare `<tech>@<ver>` is legacy and resolves differently per file (import → Ubuntu, zerops.yaml → Alpine), and `run.base` rewrites the service OS on every deploy.
+
+**Prefer Alpine** for standard apps. Switch to Ubuntu only for **glibc** needs (musl incompatibility): CGO-enabled Go, glibc-built Python/C-extension wheels, or the **Deno** runtime (Ubuntu image only). Needing a package is NOT itself a reason — both bases install packages (`sudo apk add` / `sudo apt-get install`). Use Docker only for pre-built images.
 
 ## Decision Matrix
 

apps/docs/content/guides/deployment-lifecycle.mdx

@@ -15,7 +15,7 @@ The build container is **temporary** -- created on demand, destroyed after compl
 
 **Step-by-step execution order:**
 
-1. **Container creation** -- base environment from `build.base` + `build.os` (default Alpine)
+1. **Container creation** -- base environment from `build.base` (`<os>/<tech>@<ver>`; the prefix selects Alpine or Ubuntu, a bare value resolves to Alpine)
 2. **Source code download** -- from GitHub, GitLab, or zcli push to `/var/www`
 3. **Cache restoration** -- cached files moved to `/build/source` (no-clobber, source wins)
 4. **prepareCommands** -- install additional tools/packages (skipped if cache valid)

apps/docs/content/guides/zerops-yaml-advanced.mdx

@@ -132,9 +132,10 @@ Configuration is **merged at the section level** -- child values override parent
 
 Available runtimes and versions are listed in **Service Stacks (live)** -- injected by `zerops_knowledge` and workflow responses. Some key rules:
 
-- PHP: build `php@X`, run `php-nginx@X` or `php-apache@X` (different bases)
-- Deno: REQUIRES `os: ubuntu` (no Alpine build exists). Gleam runs on both Alpine and Ubuntu.
-- Static sites: build `nodejs@latest`, run `static`
+- The OS is part of the base value — `ubuntu/nodejs@22` or `alpine/nodejs@22` — with no separate `os:` field; use the same prefix in `build.base` and `run.base` (a bare `nodejs@22` resolves to Alpine, and `run.base` rewrites the service OS on deploy)
+- PHP: build `<os>/php@X`, run `<os>/php-nginx@X` or `<os>/php-apache@X` (different bases)
+- Deno: ships only as `ubuntu/deno@X` (no Alpine image). Gleam runs on both Alpine and Ubuntu.
+- Static sites: build `alpine/nodejs@latest`, run `static`
 - `@latest` = newest stable version
 
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