refactor(platform): rename claude_bottle/bottles -> claude_bottle/platform

'bottles' was the package name when it held a single Bottle Protocol;
since we added BottlePlatform / BottlePlan / BottleCleanupPlan and
made it the home of platform dispatch, 'platform' describes the
package better. The 'bottle' concept (and the manifest field) stays.

CLI imports update from ..bottles to ..platform; internal relative
imports inside the package survive the rename unchanged. Git
detected all 7 file renames.

claude_bottle/platform/docker/__init__.py

@@ -0,0 +1,28 @@
+"""Docker bottle platform.
+
+The bulk of the implementation lives in sibling modules:
+
+  - util:                 thin Docker subprocess wrappers
+  - bottle_plan:          DockerBottlePlan
+  - bottle_cleanup_plan:  DockerBottleCleanupPlan
+  - bottle:               DockerBottle handle
+  - platform:             DockerBottlePlatform
+
+This file only re-exports the public names so
+`from claude_bottle.platform.docker import DockerBottlePlatform` keeps
+working.
+"""
+
+from __future__ import annotations
+
+from .bottle import DockerBottle
+from .bottle_cleanup_plan import DockerBottleCleanupPlan
+from .bottle_plan import DockerBottlePlan
+from .platform import DockerBottlePlatform
+
+__all__ = [
+    "DockerBottle",
+    "DockerBottleCleanupPlan",
+    "DockerBottlePlan",
+    "DockerBottlePlatform",
+]