fix(gateway): complete lazy-install rebind for slack/feishu/matrix + add ensure_and_bind helper (#25038)

Fixes #25028.

The lazy-install hooks added in #25014 installed packages correctly but
failed to rebind module-level globals after install:

- Slack: missing aiohttp rebind → NameError on file uploads
- Feishu: none of the ~25 lark_oapi symbols rebound → TypeError on
  adapter instantiation
- Matrix: mautrix.types enums stayed as stubs → mismatched values at
  runtime

Introduces tools.lazy_deps.ensure_and_bind() — a DRY helper that
combines ensure() + importer-callable + globals().update(). This
eliminates the error-prone pattern of manually listing every global
that needs updating after lazy-install. Each platform adapter now
defines a single _import() function returning all bindings.

Also fixes: pyproject.toml [slack] extra was missing aiohttp (needed
by slack-bolt's async path).

uv.lock

@@ -2092,6 +2092,7 @@ rl = [
     { name = "wandb" },
 ]
 slack = [
+    { name = "aiohttp" },
     { name = "slack-bolt" },
     { name = "slack-sdk" },
 ]
@@ -2149,6 +2150,7 @@ requires-dist = [
     { name = "agent-client-protocol", marker = "extra == 'acp'", specifier = "==0.9.0" },
     { name = "aiohttp", marker = "extra == 'homeassistant'", specifier = "==3.13.3" },
     { name = "aiohttp", marker = "extra == 'messaging'", specifier = "==3.13.3" },
+    { name = "aiohttp", marker = "extra == 'slack'", specifier = "==3.13.3" },
     { name = "aiohttp", marker = "extra == 'sms'", specifier = "==3.13.3" },
     { name = "aiohttp-socks", marker = "extra == 'matrix'", specifier = "==0.11.0" },
     { name = "aiosqlite", marker = "extra == 'matrix'", specifier = "==0.22.1" },