docs: clarify project upgrade commands

Assisted-by: OpenAI Codex (model: GPT-5, autonomous)

Author: PascalThuet

docs/upgrade.md

@@ -12,7 +12,7 @@
 | **CLI Tool — pin a version** | `specify self upgrade --tag vX.Y.Z[suffix]` | Upgrade to a specific release tag instead of the latest stable. Suffixes are limited to dev, alpha/beta/rc, and/or build metadata forms. |
 | **CLI Tool — manual fallback** | `uv tool install specify-cli --force --from git+https://github.com/github/spec-kit.git@vX.Y.Z` | When `specify self upgrade` isn't available (older installs) or when you want explicit control. |
 | **CLI Tool — manual fallback (pipx)** | `pipx install --force git+https://github.com/github/spec-kit.git@vX.Y.Z` | Same as above, for pipx installs. |
-| **Project Files** | `specify integration upgrade <key>` + `specify extension update` | Refresh installed integration files and extensions in your project |
+| **Project Files** | Run `specify integration upgrade <key>`, then `specify extension update` | Refresh installed integration files and extensions in your project |
 | **Both** | Run CLI upgrade, then project update | Recommended for major version updates |
 
 ---
@@ -150,7 +150,7 @@ Run:
 specify extension update
 ```
 
-With no extension name, this updates all installed extensions. Use `specify extension update <name>` to update only one extension. See the [extensions reference](reference/extensions.md#update-extensions) for details.
+With no extension argument, this updates all installed extensions. Use `specify extension update <extension-id-or-name>` to update only one extension. See the [extensions reference](reference/extensions.md#update-extensions) for details.
 
 ### Fallback: re-run init