docs: add Voice & Style guide and rewrite docs pages to match

Add a Voice & Style section to the docs authoring guide, then bring every
docs page in line with it: lead with the task, add success signals to
procedures, explain jargon on first use, keep bullet casing consistent,
and link out to Troubleshooting where steps can fail.

Applied across English source and all localized versions (uk, zh-cn, es,
pt-br, ko, pl).

packages/docs/content/docs/install.mdx

@@ -5,15 +5,15 @@ description: Install OpenChamber for desktop, web, or VS Code.
 
 # Install
 
-OpenChamber has three main surfaces:
+There are three ways to run OpenChamber:
 
 - desktop app for macOS
-- CLI-hosted web app with installable PWA
+- web app hosted by the CLI, which you can install like a phone app (a PWA)
 - VS Code extension
 
 ## Prerequisite
 
-Install [OpenCode](https://opencode.ai) first.
+Install [OpenCode](https://opencode.ai) first — OpenChamber runs on top of it.
 
 ## Web + PWA
 
@@ -22,12 +22,12 @@ curl -fsSL https://raw.githubusercontent.com/openchamber/openchamber/main/script
 openchamber --ui-password be-creative-here
 ```
 
-Then open the URL printed by the CLI (usually `http://localhost:3000`).
+Open the URL the CLI prints (usually `http://localhost:3000`). You should see the OpenChamber session list. To keep it handy, use your browser's "Install" option in the address bar to add it as an app.
 
 ## Desktop
 
-Download the latest desktop build from the GitHub releases page or the OpenChamber download page.
+Download the latest desktop build from the GitHub releases page or the OpenChamber download page. Open it and sign into your usual OpenCode workflow.
 
 ## VS Code
 
-Install from the VS Code Marketplace and sign into your usual OpenCode workflow.
+Install from the VS Code Marketplace and sign into your usual OpenCode workflow. The OpenChamber view then opens in the sidebar.