Split adapter.py monolith into focused modules; restore Ruff complexity defaults (issue #12)

adapter.py was a 3,493-line monolith. Split it into focused modules with
clear separation of responsibilities, bringing it down to ~857 lines:

- Module-level helpers: hooks, classify, pickers, commands, setup,
  defaults, secrets
- Frame-handler mixins: inbound, tool_frames, push_frames, media_frames,
  picker_frames, channel_frames, query_frames
- mixin_base: IrisAdapterBase (declaration-only base for shared attrs)
- adapter.py now holds only IrisAdapter (the composition of the 7 mixins
  + BasePlatformAdapter), register(), and test-facing re-exports

The mixins come before BasePlatformAdapter in the MRO so their methods
override the base; super() calls (e.g. send_image) still resolve to
BasePlatformAdapter. No circular imports; dispatch.py and http_server.py
(instance-method callers) are unaffected.

Ruff complexity ceilings (PLR0911/0912/0913/0915) restored to Ruff's
built-in defaults (12/50/6/5) instead of "just above the current maxima",
which ratchets the bar down as code grows. The existing genuinely-complex
functions (frame builders mirroring the wire schema, the QR matrix builder,
the dispatch table) carry an explicit `# noqa: PLR09xx` marking them as
reviewed, frozen exceptions; new code is held to the default ceilings.

All 125 tests green (94 test_android + 31 test_android_http); no new ruff
errors introduced.

gateway-plugin/commands.py

@@ -0,0 +1,62 @@
+"""Slash-command catalog for the app's "/" drawer.
+
+Derived from hermes' central ``COMMAND_REGISTRY`` (``hermes_cli/commands.py``)
+— the same source the gateway help text and the Telegram command menu use —
+restricted to commands available on gateway surfaces, plus plugin-registered
+commands. Never raises: any import/attribute problem (code skew between the
+plugin and the hermes checkout) degrades to an empty catalog, so the app's
+drawer simply stays closed.
+"""
+
+import logging
+from typing import Any
+
+logger = logging.getLogger(__name__)
+
+def _slash_command_catalog() -> list[dict[str, Any]]:
+    try:
+        from hermes_cli import commands as hermes_commands
+    except Exception:
+        logger.warning(
+            "iris: slash catalog unavailable (hermes_cli.commands import failed)",
+            exc_info=True,
+        )
+        return []
+
+    def _entry(
+        name: str, description: str, args_hint: str, category: str, aliases: list[str]
+    ) -> dict[str, Any]:
+        return {
+            "name": f"/{name}",
+            "description": description,
+            "args_hint": args_hint or "",
+            "category": category,
+            "aliases": [f"/{a}" for a in aliases],
+        }
+
+    entries: list[dict[str, Any]] = []
+    try:
+        overrides = hermes_commands._resolve_config_gates()
+        for cmd in hermes_commands.COMMAND_REGISTRY:
+            if not hermes_commands._is_gateway_available(cmd, overrides):
+                continue
+            entries.append(
+                _entry(cmd.name, cmd.description, cmd.args_hint, cmd.category, list(cmd.aliases))
+            )
+    except Exception:
+        # Code skew: the private helpers moved. Fall back to the plain
+        # cli_only filter (config-gated commands are dropped, acceptable).
+        logger.warning("iris: slash catalog fell back to cli_only filter", exc_info=True)
+        entries = [
+            _entry(cmd.name, cmd.description, cmd.args_hint, cmd.category, list(cmd.aliases))
+            for cmd in hermes_commands.COMMAND_REGISTRY
+            if not cmd.cli_only
+        ]
+    try:
+        for name, description, args_hint in hermes_commands._iter_plugin_command_entries():
+            entries.append(_entry(name, description, args_hint, "Plugin", []))
+    except Exception:
+        # Best-effort: a broken plugin-command registry should not break the
+        # built-in catalog, so the failure is intentionally swallowed.
+        logger.debug("iris: plugin command enumeration failed", exc_info=True)
+    return entries