feat: add permission modes and CLI orchestration layer

Permission Modes:
- Add default/plan/auto_accept modes controlling tool access
- Plan mode restricts Task agent to read-only tools only
- Auto-accept mode bypasses approval prompts (with confirmation)

Approval Scaffolding:
- Add ApprovalRule/ApprovalRuleSet for granular tool control
- Pattern-based matching on tool name and arguments
- Default rules for common safe/dangerous patterns
- Prep for future bidirectional approval flow

CLI Refactor:
- Default to Task agent (main orchestrator)
- Add --mode flag and runtime mode switching
- Integrate prompt_toolkit for better UX:
  - Persistent command history (~/.webber_history)
  - Tab completion for commands and file paths
  - Auto-suggest from history
- Deprecate standalone 'explore' command

Other:
- Split CHANGELOG.md into per-package files
- Update AGENTS.md release procedure for both packages

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

webber-cli/webber_cli/client.py

@@ -2,20 +2,36 @@
 Webber API client.
 
 Communicates with the Webber API backend for agent execution.
+Supports permission modes for controlling agent tool access.
 """
 import json
 import httpx
 from collections.abc import AsyncIterator
 from dataclasses import dataclass
+from enum import Enum
 from typing import Any
 
 
+class PermissionMode(str, Enum):
+    """
+    Permission modes controlling agent tool access.
+
+    - default: All tools available (approval may be required)
+    - plan: Read-only tools only
+    - auto_accept: All tools, no approval prompts
+    """
+    default = "default"
+    plan = "plan"
+    auto_accept = "auto_accept"
+
+
 @dataclass
 class AgentResponse:
     """Response from agent execution."""
     response: str
     agent_type: str
     success: bool
+    mode: PermissionMode = PermissionMode.default
     error: str | None = None
 
 
@@ -104,14 +120,16 @@ class WebberClient:
         agent_type: str,
         prompt: str,
         working_dir: str = ".",
+        mode: PermissionMode = PermissionMode.default,
     ) -> AgentResponse:
         """
         Run an agent with the given prompt.
 
         Args:
-            agent_type: Type of agent (e.g., "explore")
+            agent_type: Type of agent (e.g., "task")
             prompt: User prompt/query
             working_dir: Working directory for the agent
+            mode: Permission mode controlling tool access
 
         Returns:
             AgentResponse with the result
@@ -123,6 +141,7 @@ class WebberClient:
                 "agent_type": agent_type,
                 "prompt": prompt,
                 "working_dir": working_dir,
+                "mode": mode.value,
             },
         )
         response.raise_for_status()
@@ -131,6 +150,7 @@ class WebberClient:
             response=data.get("response", ""),
             agent_type=data.get("agent_type", agent_type),
             success=data.get("success", True),
+            mode=PermissionMode(data.get("mode", "default")),
             error=data.get("error"),
         )
 
@@ -139,14 +159,16 @@ class WebberClient:
         agent_type: str,
         prompt: str,
         working_dir: str = ".",
+        mode: PermissionMode = PermissionMode.default,
     ) -> AsyncIterator[str]:
         """
         Run an agent with streaming response.
 
         Args:
-            agent_type: Type of agent (e.g., "explore")
+            agent_type: Type of agent (e.g., "task")
             prompt: User prompt/query
             working_dir: Working directory for the agent
+            mode: Permission mode controlling tool access
 
         Yields:
             Text chunks as they arrive
@@ -163,6 +185,7 @@ class WebberClient:
                     "agent_type": agent_type,
                     "prompt": prompt,
                     "working_dir": working_dir,
+                    "mode": mode.value,
                 },
             ) as response:
                 response.raise_for_status()