refactor(agent_provider): drop GUEST_HOME default, backend drives guest_home

Per PR review feedback (review #130): the GUEST_HOME = '/home/node'
default in agent_provider.py was driving the wrong direction —
the agent provider shouldn't ship its own opinion about the guest
home, the backend should.

- Removes the GUEST_HOME constant.
- Makes guest_home a required kwarg on AgentProvider.provision_plan
  and the agent_provision_plan shim (no default).
- Drops module-level _SKILLS_DIR / _PROMPT_PATH constants from
  contrib/{claude,codex}/agent_provider.py; both providers now
  derive the in-guest paths from plan.workspace_plan.guest_home
  at call time, which the backend's prepare step populated.
- Updates tests/unit/test_agent_provider.py callers to pass
  guest_home explicitly. The backend prepare paths already pass
  it; no production-code call sites changed.

bot_bottle/agent_provider.py

@@ -41,8 +41,6 @@ PROVIDER_TEMPLATES = frozenset({PROVIDER_CLAUDE, PROVIDER_CODEX})
 CODEX_HOST_CREDENTIAL_HOSTS = ("api.openai.com", "chatgpt.com")
 PromptMode = Literal["append_file", "read_prompt_file"]
 
-GUEST_HOME = "/home/node"
-
 
 @dataclass(frozen=True)
 class AgentProviderRuntime:
@@ -131,7 +129,7 @@ class AgentProvider(ABC):
         *,
         dockerfile: str,
         state_dir: Path,
-        guest_home: str = GUEST_HOME,
+        guest_home: str,
         guest_env: dict[str, str] | None = None,
         auth_token: str = "",
         forward_host_credentials: bool = False,
@@ -201,7 +199,7 @@ def agent_provision_plan(
     template: str,
     dockerfile: str,
     state_dir: Path,
-    guest_home: str = GUEST_HOME,
+    guest_home: str,
     guest_env: dict[str, str] | None = None,
     auth_token: str = "",
     forward_host_credentials: bool = False,

bot_bottle/contrib/claude/agent_provider.py

@@ -15,7 +15,6 @@ from pathlib import Path
 from typing import TYPE_CHECKING
 
 from ...agent_provider import (
-    GUEST_HOME,
     AgentProvider,
     AgentProviderRuntime,
     AgentProvisionFile,
@@ -32,8 +31,14 @@ if TYPE_CHECKING:
 _REPO_ROOT = Path(__file__).resolve().parents[3]
 
 _SUPERVISE_MCP_NAME = "supervise"
-_SKILLS_DIR = f"{GUEST_HOME}/.claude/skills"
-_PROMPT_PATH = f"{GUEST_HOME}/.bot-bottle-prompt.txt"
+
+
+def _skills_dir(guest_home: str) -> str:
+    return f"{guest_home}/.claude/skills"
+
+
+def _prompt_path(guest_home: str) -> str:
+    return f"{guest_home}/.bot-bottle-prompt.txt"
 
 _RUNTIME = AgentProviderRuntime(
     template="claude",
@@ -57,7 +62,7 @@ class ClaudeAgentProvider(AgentProvider):
         *,
         dockerfile: str,
         state_dir: Path,
-        guest_home: str = GUEST_HOME,
+        guest_home: str,
         guest_env: dict[str, str] | None = None,
         auth_token: str = "",
         forward_host_credentials: bool = False,
@@ -118,7 +123,8 @@ class ClaudeAgentProvider(AgentProvider):
         agent = plan.spec.manifest.agents[plan.spec.agent_name]
         if not agent.skills:
             return
-        bottle.exec(f"mkdir -p {_SKILLS_DIR}", user="root")
+        skills_dir = _skills_dir(plan.workspace_plan.guest_home)
+        bottle.exec(f"mkdir -p {skills_dir}", user="root")
         for name in agent.skills:
             src = host_skill_dir(name)
             if not os.path.isdir(src):
@@ -126,7 +132,7 @@ class ClaudeAgentProvider(AgentProvider):
                     f"skill {name!r} disappeared from host between "
                     f"validation and copy at {src}."
                 )
-            dst = f"{_SKILLS_DIR}/{name}"
+            dst = f"{skills_dir}/{name}"
             info(f"copying skill {name} into {bottle.name}:{dst}")
             bottle.exec(f"rm -rf {dst} && mkdir -p {dst}", user="root")
             bottle.cp_in(f"{src}/.", f"{dst}/")
@@ -137,13 +143,14 @@ class ClaudeAgentProvider(AgentProvider):
         Returns the in-guest path iff the agent has a non-empty
         prompt (drives `--append-system-prompt-file`); the file is
         copied either way so the path always exists."""
-        bottle.cp_in(str(plan.prompt_file), _PROMPT_PATH)
+        prompt_path = _prompt_path(plan.workspace_plan.guest_home)
+        bottle.cp_in(str(plan.prompt_file), prompt_path)
         bottle.exec(
-            f"chown node:node {_PROMPT_PATH} && chmod 600 {_PROMPT_PATH}",
+            f"chown node:node {prompt_path} && chmod 600 {prompt_path}",
             user="root",
         )
         agent = plan.spec.manifest.agents[plan.spec.agent_name]
-        return _PROMPT_PATH if agent.prompt else None
+        return prompt_path if agent.prompt else None
 
     def provision(self, plan: "BottlePlan", bottle: "Bottle") -> None:
         """Apply the claude-side declarative provision steps from

bot_bottle/contrib/codex/agent_provider.py

@@ -16,7 +16,6 @@ from typing import TYPE_CHECKING
 
 from ...agent_provider import (
     CODEX_HOST_CREDENTIAL_HOSTS,
-    GUEST_HOME,
     AgentProvider,
     AgentProviderRuntime,
     AgentProvisionCommand,
@@ -36,11 +35,18 @@ if TYPE_CHECKING:
 _REPO_ROOT = Path(__file__).resolve().parents[3]
 
 _SUPERVISE_MCP_NAME = "supervise"
-# Codex agents still read skills from the claude-code convention
-# (~/.claude/skills/) — the bot-bottle-codex image follows the same
-# layout. If Codex grows native skill discovery later, override here.
-_SKILLS_DIR = f"{GUEST_HOME}/.claude/skills"
-_PROMPT_PATH = f"{GUEST_HOME}/.bot-bottle-prompt.txt"
+
+
+def _skills_dir(guest_home: str) -> str:
+    # Codex agents still read skills from the claude-code convention
+    # (~/.claude/skills/) — the bot-bottle-codex image follows the
+    # same layout. If Codex grows native skill discovery later,
+    # change here.
+    return f"{guest_home}/.claude/skills"
+
+
+def _prompt_path(guest_home: str) -> str:
+    return f"{guest_home}/.bot-bottle-prompt.txt"
 
 _RUNTIME = AgentProviderRuntime(
     template="codex",
@@ -64,7 +70,7 @@ class CodexAgentProvider(AgentProvider):
         *,
         dockerfile: str,
         state_dir: Path,
-        guest_home: str = GUEST_HOME,
+        guest_home: str,
         guest_env: dict[str, str] | None = None,
         auth_token: str = "",
         forward_host_credentials: bool = False,
@@ -162,7 +168,8 @@ class CodexAgentProvider(AgentProvider):
         agent = plan.spec.manifest.agents[plan.spec.agent_name]
         if not agent.skills:
             return
-        bottle.exec(f"mkdir -p {_SKILLS_DIR}", user="root")
+        skills_dir = _skills_dir(plan.workspace_plan.guest_home)
+        bottle.exec(f"mkdir -p {skills_dir}", user="root")
         for name in agent.skills:
             src = host_skill_dir(name)
             if not os.path.isdir(src):
@@ -170,7 +177,7 @@ class CodexAgentProvider(AgentProvider):
                     f"skill {name!r} disappeared from host between "
                     f"validation and copy at {src}."
                 )
-            dst = f"{_SKILLS_DIR}/{name}"
+            dst = f"{skills_dir}/{name}"
             info(f"copying skill {name} into {bottle.name}:{dst}")
             bottle.exec(f"rm -rf {dst} && mkdir -p {dst}", user="root")
             bottle.cp_in(f"{src}/.", f"{dst}/")
@@ -181,13 +188,14 @@ class CodexAgentProvider(AgentProvider):
         Codex reads it via the agent's `Read and follow the
         instructions in <path>.` bootstrap (see `prompt_args`); the
         file is copied either way so the path always exists."""
-        bottle.cp_in(str(plan.prompt_file), _PROMPT_PATH)
+        prompt_path = _prompt_path(plan.workspace_plan.guest_home)
+        bottle.cp_in(str(plan.prompt_file), prompt_path)
         bottle.exec(
-            f"chown node:node {_PROMPT_PATH} && chmod 600 {_PROMPT_PATH}",
+            f"chown node:node {prompt_path} && chmod 600 {prompt_path}",
             user="root",
         )
         agent = plan.spec.manifest.agents[plan.spec.agent_name]
-        return _PROMPT_PATH if agent.prompt else None
+        return prompt_path if agent.prompt else None
 
     def provision(self, plan: "BottlePlan", bottle: "Bottle") -> None:
         """Apply the codex-side declarative provision steps from

tests/unit/test_agent_provider.py

@@ -27,6 +27,7 @@ class TestAgentProviderRuntime(unittest.TestCase):
     def test_codex_plan_declares_home_state(self):
         with tempfile.TemporaryDirectory(prefix="bb-provider.") as tmp:
             plan = agent_provision_plan(
+                guest_home="/home/node",
                 template="codex",
                 dockerfile="/tmp/Dockerfile.codex",
                 state_dir=Path(tmp),
@@ -51,6 +52,7 @@ class TestAgentProviderRuntime(unittest.TestCase):
     def test_codex_trusts_requested_project_path(self):
         with tempfile.TemporaryDirectory(prefix="bb-provider.") as tmp:
             agent_provision_plan(
+                guest_home="/home/node",
                 template="codex",
                 dockerfile="",
                 state_dir=Path(tmp),
@@ -68,6 +70,7 @@ class TestAgentProviderRuntime(unittest.TestCase):
                 "tokens": {"access_token": _jwt(2000000000)},
             }))
             plan = agent_provision_plan(
+                guest_home="/home/node",
                 template="codex",
                 dockerfile="",
                 state_dir=Path(tmp),
@@ -87,6 +90,7 @@ class TestAgentProviderRuntime(unittest.TestCase):
     def test_claude_with_auth_token_injects_provider_route_and_placeholder(self):
         with tempfile.TemporaryDirectory(prefix="bb-provider.") as tmp:
             plan = agent_provision_plan(
+                guest_home="/home/node",
                 template="claude",
                 dockerfile="/tmp/Dockerfile.claude",
                 state_dir=Path(tmp),
@@ -109,6 +113,7 @@ class TestAgentProviderRuntime(unittest.TestCase):
     def test_claude_trusts_requested_project_path(self):
         with tempfile.TemporaryDirectory(prefix="bb-provider.") as tmp:
             agent_provision_plan(
+                guest_home="/home/node",
                 template="claude",
                 dockerfile="",
                 state_dir=Path(tmp),
@@ -127,6 +132,7 @@ class TestAgentProviderRuntime(unittest.TestCase):
                 "tokens": {"access_token": _jwt(2000000000)},
             }))
             plan = agent_provision_plan(
+                guest_home="/home/node",
                 template="codex",
                 dockerfile="",
                 state_dir=Path(tmp),
@@ -143,6 +149,7 @@ class TestAgentProviderRuntime(unittest.TestCase):
     def test_codex_without_forward_host_credentials_has_passthrough_egress_routes(self):
         with tempfile.TemporaryDirectory(prefix="bb-provider.") as tmp:
             plan = agent_provision_plan(
+                guest_home="/home/node",
                 template="codex",
                 dockerfile="",
                 state_dir=Path(tmp),
@@ -160,6 +167,7 @@ class TestAgentProviderRuntime(unittest.TestCase):
     def test_claude_without_auth_token_has_passthrough_egress_route(self):
         with tempfile.TemporaryDirectory(prefix="bb-provider.") as tmp:
             plan = agent_provision_plan(
+                guest_home="/home/node",
                 template="claude",
                 dockerfile="",
                 state_dir=Path(tmp),
@@ -183,6 +191,7 @@ class TestAgentProviderRuntime(unittest.TestCase):
                 "tokens": {"access_token": access},
             }))
             plan = agent_provision_plan(
+                guest_home="/home/node",
                 template="codex",
                 dockerfile="",
                 state_dir=Path(tmp),
@@ -197,6 +206,7 @@ class TestAgentProviderRuntime(unittest.TestCase):
     def test_codex_without_forward_host_credentials_has_empty_provisioned_env(self):
         with tempfile.TemporaryDirectory(prefix="bb-provider.") as tmp:
             plan = agent_provision_plan(
+                guest_home="/home/node",
                 template="codex",
                 dockerfile="",
                 state_dir=Path(tmp),