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/image-generation.md

@@ -141,10 +141,25 @@ Debug logs are saved to `./logs/image_tools_debug_<session_id>.json` with detail
 
 The image generation tool runs with safety checks disabled by default (`safety_tolerance: 5`, the most permissive setting). This is configured at the code level and is not user-adjustable.
 
+## Platform Delivery
+
+Generated images are delivered differently depending on the platform:
+
+| Platform | Delivery method |
+|----------|----------------|
+| **CLI** | Image URL printed as markdown `![description](url)` — click to open in browser |
+| **Telegram** | Image sent as a photo message with the prompt as caption |
+| **Discord** | Image embedded in a message |
+| **Slack** | Image URL in message (Slack unfurls it) |
+| **WhatsApp** | Image sent as a media message |
+| **Other platforms** | Image URL in plain text |
+
+The agent uses `MEDIA:<url>` syntax in its response, which the platform adapter converts to the appropriate format.
+
 ## Limitations
 
 - **Requires FAL API key** — image generation incurs API costs on your FAL.ai account
 - **No image editing** — this is text-to-image only, no inpainting or img2img
-- **URL-based delivery** — images are returned as temporary FAL.ai URLs, not saved locally
+- **URL-based delivery** — images are returned as temporary FAL.ai URLs, not saved locally. URLs expire after a period (typically hours)
 - **Upscaling adds latency** — the automatic 2x upscale step adds processing time
 - **Max 4 images per request** — `num_images` is capped at 4