docs: full-page readability pass on 5 worst-offender pages

- automation/standing-orders: sentence-case all H2/H3 headings (Why Standing Orders, Anatomy, Execute-Verify-Report Pattern, Multi-Program Architecture, Best Practices, etc.) and clean up Related link styling
- platforms/raspberry-pi: sentence-case 10 headings (Hardware Requirements, Performance Optimizations, Cost Comparison, etc.)
- install/fly: sentence-case troubleshooting and Private Deployment headings
- pi-dev: drop 'this guide summarizes' filler, sentence-case 4 H2 headings, restore brand-cased Pi
- concepts/model-providers: sentence-case Kimi Coding (other brand-named providers preserved as-is: Google Gemini, Google Vertex, Kilo Gateway, Volcano Engine)

docs/install/fly.md

@@ -295,7 +295,7 @@ fly machine update <machine-id> --vm-memory 2048 -y
 
 **Note:** 512MB is too small. 1GB may work but can OOM under load or with verbose logging. **2GB is recommended.**
 
-### Gateway Lock Issues
+### Gateway lock issues
 
 Gateway refuses to start with "already running" errors.
 
@@ -310,7 +310,7 @@ fly machine restart <machine-id>
 
 The lock file is at `/data/gateway.*.lock` (not in a subdirectory).
 
-### Config Not Being Read
+### Config not being read
 
 `--allow-unconfigured` only bypasses the startup guard. It does not create or repair `/data/openclaw.json`, so make sure your real config exists and includes `gateway.mode="local"` when you want a normal local gateway start.
 
@@ -320,7 +320,7 @@ Verify the config exists:
 fly ssh console --command "cat /data/openclaw.json"
 ```
 
-### Writing Config via SSH
+### Writing config via SSH
 
 The `fly ssh console -C` command doesn't support shell redirection. To write a config file:
 
@@ -339,7 +339,7 @@ fly sftp shell
 fly ssh console --command "rm /data/openclaw.json"
 ```
 
-### State Not Persisting
+### State not persisting
 
 If you lose auth profiles, channel/provider state, or sessions after a restart,
 the state dir is writing to the container filesystem.
@@ -360,7 +360,7 @@ fly status
 fly logs
 ```
 
-### Updating Machine Command
+### Updating machine command
 
 If you need to change the startup command without a full redeploy:
 
@@ -377,7 +377,7 @@ fly machine update <machine-id> --vm-memory 2048 --command "node dist/index.js g
 
 **Note:** After `fly deploy`, the machine command may reset to what's in `fly.toml`. If you made manual changes, re-apply them after deploy.
 
-## Private Deployment (Hardened)
+## Private deployment (hardened)
 
 By default, Fly allocates public IPs, making your gateway accessible at `https://your-app.fly.dev`. This is convenient but means your deployment is discoverable by internet scanners (Shodan, Censys, etc.).