docs: comprehensive update for recent merged PRs (#9019)

Audit and update documentation across 12 files to match changes from
~50 recently merged PRs. Key updates:

Slash commands (slash-commands.md):
- Add 5 missing commands: /snapshot, /fast, /image, /debug, /restart
- Fix /status incorrectly labeled as messaging-only (available in both)
- Add --global flag to /model docs
- Add [focus topic] arg to /compress docs

CLI commands (cli-commands.md):
- Add hermes debug share section with options and examples
- Add hermes backup section with --quick and --label flags
- Add hermes import section

Feature docs:
- TTS: document global tts.speed and per-provider speed for Edge/OpenAI
- Web dashboard: add docs for 5 missing pages (Sessions, Logs,
  Analytics, Cron, Skills) and 15+ API endpoints
- WhatsApp: add streaming, 4K chunking, and markdown formatting docs
- Skills: add GitHub rate-limit/GITHUB_TOKEN troubleshooting tip
- Budget: document CLI notification on iteration budget exhaustion

Config migration (compression.summary_* → auxiliary.compression.*):
- Update configuration.md, environment-variables.md,
  fallback-providers.md, cli.md, and context-compression-and-caching.md
- Replace legacy compression.summary_model/provider/base_url references
  with auxiliary.compression.model/provider/base_url
- Add legacy migration info boxes explaining auto-migration

Minor fixes:
- wecom-callback.md: clarify 'text only' limitation (input only)
- Escape {session_id}/{job_id} in web-dashboard.md headings for MDX

website/docs/reference/slash-commands.md

@@ -28,8 +28,9 @@ Type `/` in the CLI to open the autocomplete menu. Built-in commands are case-in
 | `/retry` | Retry the last message (resend to agent) |
 | `/undo` | Remove the last user/assistant exchange |
 | `/title` | Set a title for the current session (usage: /title My Session Name) |
-| `/compress` | Manually compress conversation context (flush memories + summarize) |
+| `/compress [focus topic]` | Manually compress conversation context (flush memories + summarize). Optional focus topic narrows what the summary preserves. |
 | `/rollback` | List or restore filesystem checkpoints (usage: /rollback [number]) |
+| `/snapshot [create\|restore <id>\|prune]` (alias: `/snap`) | Create or restore state snapshots of Hermes config/state. `create [label]` saves a snapshot, `restore <id>` reverts to it, `prune [N]` removes old snapshots, or list all with no args. |
 | `/stop` | Kill all running background processes |
 | `/queue <prompt>` (alias: `/q`) | Queue a prompt for the next turn (doesn't interrupt the current agent response). **Note:** `/q` is claimed by both `/queue` and `/quit`; the last registration wins, so `/q` resolves to `/quit` in practice. Use `/queue` explicitly. |
 | `/resume [name]` | Resume a previously-named session |
@@ -44,11 +45,12 @@ Type `/` in the CLI to open the autocomplete menu. Built-in commands are case-in
 | Command | Description |
 |---------|-------------|
 | `/config` | Show current configuration |
-| `/model [model-name]` | Show or change the current model. Supports: `/model claude-sonnet-4`, `/model provider:model` (switch providers), `/model custom:model` (custom endpoint), `/model custom:name:model` (named custom provider), `/model custom` (auto-detect from endpoint) |
+| `/model [model-name]` | Show or change the current model. Supports: `/model claude-sonnet-4`, `/model provider:model` (switch providers), `/model custom:model` (custom endpoint), `/model custom:name:model` (named custom provider), `/model custom` (auto-detect from endpoint). Use `--global` to persist the change to config.yaml. |
 | `/provider` | Show available providers and current provider |
 | `/personality` | Set a predefined personality |
 | `/verbose` | Cycle tool progress display: off → new → all → verbose. Can be [enabled for messaging](#notes) via config. |
 | `/reasoning` | Manage reasoning effort and display (usage: /reasoning [level\|show\|hide]) |
+| `/fast [normal\|fast\|status]` | Toggle fast mode — OpenAI Priority Processing / Anthropic Fast Mode. Options: `normal`, `fast`, `status`, `on`, `off`. |
 | `/skin` | Show or change the display skin/theme |
 | `/voice [on\|off\|tts\|status]` | Toggle CLI voice mode and spoken playback. Recording uses `voice.record_key` (default: `Ctrl+B`). |
 | `/yolo` | Toggle YOLO mode — skip all dangerous command approval prompts. |
@@ -75,6 +77,8 @@ Type `/` in the CLI to open the autocomplete menu. Built-in commands are case-in
 | `/insights` | Show usage insights and analytics (last 30 days) |
 | `/platforms` (alias: `/gateway`) | Show gateway/messaging platform status |
 | `/paste` | Check clipboard for an image and attach it |
+| `/image <path>` | Attach a local image file for your next prompt. |
+| `/debug` | Upload debug report (system info + logs) and get shareable links. Also available in messaging. |
 | `/profile` | Show active profile name and home directory |
 
 ### Exit
@@ -117,13 +121,14 @@ The messaging gateway supports the following built-in commands inside Telegram,
 | `/reset` | Reset conversation history. |
 | `/status` | Show session info. |
 | `/stop` | Kill all running background processes and interrupt the running agent. |
-| `/model [provider:model]` | Show or change the model. Supports provider switches (`/model zai:glm-5`), custom endpoints (`/model custom:model`), named custom providers (`/model custom:local:qwen`), and auto-detect (`/model custom`). |
+| `/model [provider:model]` | Show or change the model. Supports provider switches (`/model zai:glm-5`), custom endpoints (`/model custom:model`), named custom providers (`/model custom:local:qwen`), and auto-detect (`/model custom`). Use `--global` to persist the change to config.yaml. |
 | `/provider` | Show provider availability and auth status. |
 | `/personality [name]` | Set a personality overlay for the session. |
+| `/fast [normal\|fast\|status]` | Toggle fast mode — OpenAI Priority Processing / Anthropic Fast Mode. |
 | `/retry` | Retry the last message. |
 | `/undo` | Remove the last exchange. |
 | `/sethome` (alias: `/set-home`) | Mark the current chat as the platform home channel for deliveries. |
-| `/compress` | Manually compress conversation context. |
+| `/compress [focus topic]` | Manually compress conversation context. Optional focus topic narrows what the summary preserves. |
 | `/title [name]` | Set or show the session title. |
 | `/resume [name]` | Resume a previously named session. |
 | `/usage` | Show token usage, estimated cost breakdown (input/output), context window state, and session duration. |
@@ -131,6 +136,7 @@ The messaging gateway supports the following built-in commands inside Telegram,
 | `/reasoning [level\|show\|hide]` | Change reasoning effort or toggle reasoning display. |
 | `/voice [on\|off\|tts\|join\|channel\|leave\|status]` | Control spoken replies in chat. `join`/`channel`/`leave` manage Discord voice-channel mode. |
 | `/rollback [number]` | List or restore filesystem checkpoints. |
+| `/snapshot [create\|restore <id>\|prune]` (alias: `/snap`) | Create or restore state snapshots of Hermes config/state. |
 | `/background <prompt>` | Run a prompt in a separate background session. Results are delivered back to the same chat when the task finishes. See [Messaging Background Sessions](/docs/user-guide/messaging/#background-sessions). |
 | `/plan [request]` | Load the bundled `plan` skill to write a markdown plan instead of executing the work. Plans are saved under `.hermes/plans/` relative to the active workspace/backend working directory. |
 | `/reload-mcp` (alias: `/reload_mcp`) | Reload MCP servers from config. |
@@ -140,13 +146,15 @@ The messaging gateway supports the following built-in commands inside Telegram,
 | `/approve [session\|always]` | Approve and execute a pending dangerous command. `session` approves for this session only; `always` adds to permanent allowlist. |
 | `/deny` | Reject a pending dangerous command. |
 | `/update` | Update Hermes Agent to the latest version. |
+| `/restart` | Gracefully restart the gateway after draining active runs. When the gateway comes back online, it sends a confirmation to the requester's chat/thread. |
+| `/debug` | Upload debug report (system info + logs) and get shareable links. |
 | `/help` | Show messaging help. |
 | `/<skill-name>` | Invoke any installed skill by name. |
 
 ## Notes
 
-- `/skin`, `/tools`, `/toolsets`, `/browser`, `/config`, `/cron`, `/skills`, `/platforms`, `/paste`, `/statusbar`, and `/plugins` are **CLI-only** commands.
+- `/skin`, `/tools`, `/toolsets`, `/browser`, `/config`, `/cron`, `/skills`, `/platforms`, `/paste`, `/image`, `/statusbar`, and `/plugins` are **CLI-only** commands.
 - `/verbose` is **CLI-only by default**, but can be enabled for messaging platforms by setting `display.tool_progress_command: true` in `config.yaml`. When enabled, it cycles the `display.tool_progress` mode and saves to config.
-- `/status`, `/sethome`, `/update`, `/approve`, `/deny`, and `/commands` are **messaging-only** commands.
-- `/background`, `/voice`, `/reload-mcp`, `/rollback`, and `/yolo` work in **both** the CLI and the messaging gateway.
+- `/sethome`, `/update`, `/restart`, `/approve`, `/deny`, and `/commands` are **messaging-only** commands.
+- `/status`, `/background`, `/voice`, `/reload-mcp`, `/rollback`, `/snapshot`, `/debug`, `/fast`, and `/yolo` work in **both** the CLI and the messaging gateway.
 - `/voice join`, `/voice channel`, and `/voice leave` are only meaningful on Discord.