docs: sentence-case sweep across 4 more pages

- platforms/digitalocean: Cost Comparison (2026), Oracle Cloud Free Alternative
- gateway/remote-gateway-readme: Quick Setup, How It Works
- cli/crestodian: Setup Bootstrap
- plugins/codex-harness: Computer Use
(Brand-named headings preserved across azure.md, web.md, firecrawl.md, clawhub.md, config-channels.md, security/index.md.)

docs/cli/crestodian.md

@@ -129,7 +129,7 @@ Discovery is not audited. Only applied operations and writes are logged.
 `openclaw onboard --modern` starts Crestodian as the modern onboarding preview.
 Plain `openclaw onboard` still runs classic onboarding.
 
-## Setup Bootstrap
+## Setup bootstrap
 
 `setup` is the chat-first onboarding bootstrap. It writes only through typed
 config operations and asks for approval first.

docs/gateway/remote-gateway-readme.md

@@ -33,7 +33,7 @@ flowchart TB
     T --> C
 ```
 
-## Quick Setup
+## Quick setup
 
 ### Step 1: Add SSH Config
 
@@ -152,7 +152,7 @@ launchctl bootout gui/$UID/ai.openclaw.ssh-tunnel
 
 ---
 
-## How It Works
+## How it works
 
 | Component                            | What It Does                                                 |
 | ------------------------------------ | ------------------------------------------------------------ |

docs/platforms/digitalocean.md

@@ -14,7 +14,7 @@ Run a persistent OpenClaw Gateway on DigitalOcean for **$6/month** (or $4/mo wit
 
 If you want a $0/month option and don’t mind ARM + provider-specific setup, see the [Oracle Cloud guide](/platforms/oracle).
 
-## Cost Comparison (2026)
+## Cost comparison (2026)
 
 | Provider     | Plan            | Specs                  | Price/mo    | Notes                                 |
 | ------------ | --------------- | ---------------------- | ----------- | ------------------------------------- |
@@ -209,7 +209,7 @@ openclaw backup create
 
 ---
 
-## Oracle Cloud Free Alternative
+## Oracle Cloud free alternative
 
 Oracle Cloud offers **Always Free** ARM instances that are significantly more powerful than any paid option here — for $0/month.
 

docs/plugins/codex-harness.md

@@ -542,7 +542,7 @@ Environment overrides remain available for local testing:
 preferred for repeatable deployments because it keeps the plugin behavior in the
 same reviewed file as the rest of the Codex harness setup.
 
-## Computer Use
+## Computer use
 
 Computer Use is a Codex-native MCP plugin. OpenClaw does not vendor the desktop
 control app or execute desktop actions itself; it enables Codex app-server