fix: revert unsafe permission changes from PR #78

Security fixes to restore defense-in-depth after merging PR #78:

**client.py:**
- Revert permission mode from "bypassPermissions" to "acceptEdits"
- Remove redundant web_tools_auto_approve_hook from PreToolUse hooks
- Remove unused import of web_tools_auto_approve_hook

**security.py:**
- Remove web_tools_auto_approve_hook function (was redundant and
  returned {} for ALL tools, not just WebFetch/WebSearch)

**server/services/spec_chat_session.py:**
- Restore allowed_tools restriction: [Read, Write, Edit, Glob,
  WebFetch, WebSearch]
- Revert permission mode from "bypassPermissions" to "acceptEdits"
- Keeps setting_sources=["project", "user"] for global skills access

**ui/src/components/AgentAvatar.tsx:**
- Remove unused getMascotName export to fix React Fast Refresh warning
- File now only exports AgentAvatar component as expected

The bypassPermissions mode combined with unrestricted tool access in
spec_chat_session.py created a security gap where Bash commands could
execute without validation (sandbox disabled, no bash_security_hook).

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

client.py

@@ -15,7 +15,7 @@ from claude_agent_sdk import ClaudeAgentOptions, ClaudeSDKClient
 from claude_agent_sdk.types import HookMatcher
 from dotenv import load_dotenv
 
-from security import bash_security_hook, web_tools_auto_approve_hook
+from security import bash_security_hook
 
 # Load environment variables from .env file if present
 load_dotenv()
@@ -181,7 +181,7 @@ def create_client(
     security_settings = {
         "sandbox": {"enabled": True, "autoAllowBashIfSandboxed": True},
         "permissions": {
-            "defaultMode": "bypassPermissions",  # Auto-approve all tools
+            "defaultMode": "acceptEdits",  # Auto-approve edits within allowed directories
             "allow": permissions_list,
         },
     }
@@ -273,7 +273,6 @@ def create_client(
             hooks={
                 "PreToolUse": [
                     HookMatcher(matcher="Bash", hooks=[bash_security_hook]),
-                    HookMatcher(matcher="WebFetch|WebSearch", hooks=[web_tools_auto_approve_hook]),
                 ],
             },
             max_turns=1000,