docs: fix stale and incorrect documentation across 18 files

Cross-referenced all 84 docs pages against the actual codebase and
corrected every discrepancy found.

Reference docs:
- faq.md: Fix non-existent commands (/stats→/usage, /context→/usage,
  hermes models→hermes model, hermes config get→hermes config show,
  hermes gateway logs→cat gateway.log, async→sync chat() call)
- cli-commands.md: Fix --provider choices list (remove providers not
  in argparse), add undocumented -s/--skills flag
- slash-commands.md: Add missing /queue and /resume commands, fix
  /approve args_hint to show [session|always]
- tools-reference.md: Remove duplicate vision and web toolset sections
- environment-variables.md: Fix HERMES_INFERENCE_PROVIDER list (add
  copilot-acp, remove alibaba to match actual argparse choices)

Configuration & user guide:
- configuration.md: Fix approval_mode→approvals.mode (manual not ask),
  checkpoints.enabled default true not false, human_delay defaults
  (500/2000→800/2500), remove non-existent delegation.max_iterations
  and delegation.default_toolsets, fix website_blocklist nesting
  under security:, add .hermes.md and CLAUDE.md to context files
  table with priority system explanation
- security.md: Fix website_blocklist nesting under security:
- context-files.md: Add .hermes.md/HERMES.md and CLAUDE.md support,
  document priority-based first-match-wins loading behavior
- cli.md: Fix personalities config nesting (top-level, not under agent:)
- delegation.md: Fix model override docs (config-level, not per-call
  tool parameter)
- rl-training.md: Fix log directory (tinker-atropos/logs/→
  ~/.hermes/logs/rl_training/)
- tts.md: Fix Discord delivery format (voice bubble with fallback,
  not just file attachment)
- git-worktrees.md: Remove outdated v0.2.0 version reference

Developer guide:
- prompt-assembly.md: Add .hermes.md, CLAUDE.md, document priority
  system for context files
- agent-loop.md: Fix callback list (remove non-existent
  message_callback, add stream_delta_callback, tool_gen_callback,
  status_callback)

Messaging & guides:
- webhooks.md: Fix command (hermes setup gateway→hermes gateway setup)
- tips.md: Fix session idle timeout (120min→24h), config file
  (gateway.json→config.yaml)
- build-a-hermes-plugin.md: Fix plugin.yaml provides: format
  (provides_tools/provides_hooks as lists), note register_command()
  as not yet implemented

website/docs/user-guide/security.md

@@ -296,13 +296,14 @@ You can restrict which websites the agent can access through its web and browser
 
 ```yaml
 # In ~/.hermes/config.yaml
-website_blocklist:
-  enabled: true
-  domains:
-    - "*.internal.company.com"
-    - "admin.example.com"
-  shared_files:
-    - "/etc/hermes/blocked-sites.txt"
+security:
+  website_blocklist:
+    enabled: true
+    domains:
+      - "*.internal.company.com"
+      - "admin.example.com"
+    shared_files:
+      - "/etc/hermes/blocked-sites.txt"
 ```
 
 When a blocked URL is requested, the tool returns an error explaining the domain is blocked by policy. The blocklist is enforced across `web_search`, `web_extract`, `browser_navigate`, and all URL-capable tools.