docs: comprehensive documentation audit — fix stale info, expand thin pages, add depth (#5393)

Major changes across 20 documentation pages:

Staleness fixes:
- Fix FAQ: wrong import path (hermes.agent → run_agent)
- Fix FAQ: stale Gemini 2.0 model → Gemini 3 Flash
- Fix integrations/index: missing MiniMax TTS provider
- Fix integrations/index: web_crawl is not a registered tool
- Fix sessions: add all 19 session sources (was only 5)
- Fix cron: add all 18 delivery targets (was only telegram/discord)
- Fix webhooks: add all delivery targets
- Fix overview: add missing MCP, memory providers, credential pools
- Fix all line-number references → use function name searches instead
- Update file size estimates (run_agent ~9200, gateway ~7200, cli ~8500)

Expanded thin pages (< 150 lines → substantial depth):
- honcho.md: 43 → 108 lines — added feature comparison, tools, config, CLI
- overview.md: 49 → 55 lines — added MCP, memory providers, credential pools
- toolsets-reference.md: 57 → 175 lines — added explanations, config examples,
  custom toolsets, wildcards, platform differences table
- optional-skills-catalog.md: 74 → 153 lines — added 25+ missing skills across
  communication, devops, mlops (18!), productivity, research categories
- integrations/index.md: 82 → 115 lines — added messaging, HA, plugins sections
- cron-internals.md: 90 → 195 lines — added job JSON example, lifecycle states,
  tick cycle, delivery targets, script-backed jobs, CLI interface
- gateway-internals.md: 111 → 250 lines — added architecture diagram, message
  flow, two-level guard, platform adapters, token locks, process management
- agent-loop.md: 112 → 235 lines — added entry points, API mode resolution,
  turn lifecycle detail, message alternation rules, tool execution flow,
  callback table, budget tracking, compression details
- architecture.md: 152 → 295 lines — added system overview diagram, data flow
  diagrams, design principles table, dependency chain

Other depth additions:
- context-references.md: added platform availability, compression interaction,
  common patterns sections
- slash-commands.md: added quick commands config example, alias resolution
- image-generation.md: added platform delivery table
- tools-reference.md: added tool counts, MCP tools note
- index.md: updated platform count (5 → 14+), tool count (40+ → 47)

website/docs/user-guide/features/cron.md

@@ -187,9 +187,21 @@ When scheduling jobs, you specify where the output goes:
 | `"origin"` | Back to where the job was created | Default on messaging platforms |
 | `"local"` | Save to local files only (`~/.hermes/cron/output/`) | Default on CLI |
 | `"telegram"` | Telegram home channel | Uses `TELEGRAM_HOME_CHANNEL` |
-| `"discord"` | Discord home channel | Uses `DISCORD_HOME_CHANNEL` |
 | `"telegram:123456"` | Specific Telegram chat by ID | Direct delivery |
-| `"discord:987654"` | Specific Discord channel by ID | Direct delivery |
+| `"telegram:-100123:17585"` | Specific Telegram topic | `chat_id:thread_id` format |
+| `"discord"` | Discord home channel | Uses `DISCORD_HOME_CHANNEL` |
+| `"discord:#engineering"` | Specific Discord channel | By channel name |
+| `"slack"` | Slack home channel | |
+| `"whatsapp"` | WhatsApp home | |
+| `"signal"` | Signal | |
+| `"matrix"` | Matrix home room | |
+| `"mattermost"` | Mattermost home channel | |
+| `"email"` | Email | |
+| `"sms"` | SMS via Twilio | |
+| `"homeassistant"` | Home Assistant | |
+| `"dingtalk"` | DingTalk | |
+| `"feishu"` | Feishu/Lark | |
+| `"wecom"` | WeCom | |
 
 The agent's final response is automatically delivered. You do not need to call `send_message` in the cron prompt.