refactor(gateway): migrate slack/dingtalk/whatsapp/matrix/feishu/telegram/wecom/email/sms adapters to bundled plugins

Salvage of PR #41284 onto current main. Relocates the last 9 inline messaging
adapters (+ satellites: telegram_network, feishu_comment/_rules/meeting_invite,
wecom_crypto, wecom_callback) from gateway/platforms/ into self-contained
bundled plugins under plugins/platforms/<x>/, discovered via the platform
registry. Strips the per-platform core touchpoints from gateway/run.py,
gateway/config.py, hermes_cli/gateway.py, hermes_cli/setup.py, and
tools/send_message_tool.py.

Carries forward the migration fixes (explicit enabled:false honored,
get_connected_platforms forces discovery, plugin is_connected via
gateway.get_env_value, logs --component gateway matches plugins.platforms.*,
matrix hidden on Windows).

Additionally ports config keys main added since the PR base: the matrix
plugin's _apply_yaml_config now also covers allowed_users,
ignore_user_patterns, process_notices, and session_scope (the inline
gateway/config.py matrix block gained these in the 1340 commits the PR sat
open; they would otherwise have been silently dropped on deletion).

hermes_logging.py

@@ -210,7 +210,11 @@ class _ComponentFilter(logging.Filter):
 # Logger name prefixes that belong to each component.
 # Used by _ComponentFilter and exposed for ``hermes logs --component``.
 COMPONENT_PREFIXES = {
-    "gateway": ("gateway", "hermes_plugins"),
+    # ``plugins.platforms`` covers messaging-platform adapters that migrated
+    # out of ``gateway/platforms/`` into bundled plugins (#41112) — they are
+    # still gateway components and their logs belong in gateway.log / match
+    # ``hermes logs --component gateway``.
+    "gateway": ("gateway", "hermes_plugins", "plugins.platforms"),
     "agent": ("agent", "run_agent", "model_tools", "batch_runner"),
     "tools": ("tools",),
     "cli": ("hermes_cli", "cli"),