docs: surface 'hermes setup --portal' and 'hermes portal' across user-facing pages (#30869)

PR #30860 added a one-shot Portal setup command and a small portal CLI
surface. Update the docs so the new commands are discoverable without
upgrading the tone of existing Portal mentions.

- getting-started/quickstart.md: small tip near Choose a Provider
  pointing at 'hermes setup --portal' as the easiest fresh-install path.
- user-guide/features/tool-gateway.md: lead the Get-Started section
  with 'hermes setup --portal' for fresh installs, keep 'hermes model'
  for already-configured users, and add 'hermes portal status / tools'
  to the activity-check commands.
- user-guide/features/{web-search,image-generation,tts,browser}.md: the
  existing 'Nous Subscribers' tip blocks now name the one-shot command
  for new installs, keeping the existing 'hermes tools' path for users
  who only want to swap a single backend.
- reference/cli-commands.md: register 'hermes portal' in the top-level
  command table, add a 'hermes portal' section with subcommands, and
  add '--portal' to the 'hermes setup' options table.

Tone: each page already had a Portal mention. This PR keeps the per-page
count to one and uses concrete CLI commands rather than promotional copy.
Tool Gateway page is the one exception (the whole doc is about Portal).

website/docs/user-guide/features/tool-gateway.md

@@ -39,8 +39,16 @@ Bring your own keys anytime — per-tool, whenever you want to. The gateway isn'
 
 ## Get started
 
+The fastest path for a fresh install:
+
 ```bash
-hermes model          # Pick Nous Portal as your provider
+hermes setup --portal     # Nous OAuth, set Nous as provider, and turn on the Tool Gateway in one go
+```
+
+Already have Hermes configured? Just switch your provider:
+
+```bash
+hermes model              # Pick Nous Portal — Hermes will offer to turn on the Tool Gateway
 ```
 
 When you select Nous Portal, Hermes offers to turn on the Tool Gateway. Accept, and you're done — every supported tool is live on the next run.
@@ -48,10 +56,12 @@ When you select Nous Portal, Hermes offers to turn on the Tool Gateway. Accept,
 Check what's active at any time:
 
 ```bash
-hermes status
+hermes portal status      # Portal auth + Tool Gateway routing summary
+hermes portal tools       # Gateway catalog with current routing per tool
+hermes status             # Full system status (Tool Gateway is one section)
 ```
 
-You'll see a section like:
+`hermes portal status` shows a section like:
 
 ```
 ◆ Nous Tool Gateway