Update CLI documentation for clarity and accuracy

docs/en/guide/cli-reference.md

@@ -516,10 +516,3 @@ spc spc-config "bcmath,openssl" --libs
 # Use absolute library paths
 spc spc-config "bcmath,openssl" --libs --absolute-libs
 ```
-Enter an interactive shell with StaticPHP's build environment pre-loaded (compiler wrappers, `buildroot/`, `pkgroot/` paths, etc. on `PATH`).
-
-```bash
-spc dev:shell
-```
-
-Useful for compiling small programs against `libphp.a` (embed SAPI) or inspecting the build environment manually.

docs/en/guide/first-build.md

@@ -74,6 +74,10 @@ This approach lets you run download and compile as separate steps — useful whe
 
 ### Step 1: Download Dependencies
 
+In v3, you can skip this step entirely — running `build:php` directly will automatically download any missing artifacts.
+
+If you want to pre-download ahead of time, or if you're working in a slow-network environment and want to separate the download phase, use the `download` command:
+
 ```bash
 # Download only what the chosen extensions need (recommended)
 spc download --for-extensions="bcmath,posix,phar,zlib,openssl,curl,fileinfo,tokenizer" --with-php=8.4

docs/en/guide/installation.md

@@ -82,13 +82,6 @@ The script downloads `php` and `composer` into a `runtime/` subdirectory. You th
    # Add this to ~/.bashrc or ~/.zshrc to make it permanent
    ```
 
-::: tip
-In regions with restricted access to GitHub or getcomposer.org, pass `--mirror china` to use a mirror:
-```bash
-bin/setup-runtime --mirror china
-```
-:::
-
 ## Vendor mode
 
 If you already have a PHP project and want to call StaticPHP's build APIs directly, or use a custom registry to support private libraries and extensions, pull it in as a Composer dependency: