feat: add configurable CLI command and UI improvements

Add support for alternative CLI commands via CLI_COMMAND environment
variable, allowing users to use CLIs other than 'claude' (e.g., 'glm').
This change affects all server services and the main CLI launcher.

Key changes:

- Configurable CLI command via CLI_COMMAND env var (defaults to 'claude')
- Configurable Playwright headless mode via PLAYWRIGHT_HEADLESS env var
- Pin claude-agent-sdk version to <0.2.0 for stability
- Use tail -500 for progress notes to avoid context overflow
- Add project delete functionality with confirmation dialog
- Replace single-line input with resizable textarea in spec chat
- Add coder agent configuration for code implementation tasks
- Ignore issues/ directory in git

Files modified:
- client.py: CLI command and Playwright headless configuration
- server/main.py, server/services/*: CLI command configuration
- start.py: CLI command configuration and error messages
- .env.example: Document new environment variables
- .gitignore: Ignore issues/ directory
- requirements.txt: Pin SDK version
- .claude/templates/*: Use tail -500 for progress notes
- ui/src/components/ProjectSelector.tsx: Add delete button
- ui/src/components/SpecCreationChat.tsx: Auto-resizing textarea
- ui/src/components/ConfirmDialog.tsx: New reusable dialog
- .claude/agents/coder.md: New coder agent configuration

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

ui/src/components/ProjectSelector.tsx

@@ -1,7 +1,9 @@
 import { useState } from 'react'
-import { ChevronDown, Plus, FolderOpen, Loader2 } from 'lucide-react'
+import { ChevronDown, Plus, FolderOpen, Loader2, Trash2 } from 'lucide-react'
 import type { ProjectSummary } from '../lib/types'
 import { NewProjectModal } from './NewProjectModal'
+import { ConfirmDialog } from './ConfirmDialog'
+import { useDeleteProject } from '../hooks/useProjects'
 
 interface ProjectSelectorProps {
   projects: ProjectSummary[]
@@ -18,12 +20,42 @@ export function ProjectSelector({
 }: ProjectSelectorProps) {
   const [isOpen, setIsOpen] = useState(false)
   const [showNewProjectModal, setShowNewProjectModal] = useState(false)
+  const [projectToDelete, setProjectToDelete] = useState<string | null>(null)
+
+  const deleteProject = useDeleteProject()
 
   const handleProjectCreated = (projectName: string) => {
     onSelectProject(projectName)
     setIsOpen(false)
   }
 
+  const handleDeleteClick = (e: React.MouseEvent, projectName: string) => {
+    // Prevent the click from selecting the project
+    e.stopPropagation()
+    setProjectToDelete(projectName)
+  }
+
+  const handleConfirmDelete = async () => {
+    if (!projectToDelete) return
+
+    try {
+      await deleteProject.mutateAsync(projectToDelete)
+      // If the deleted project was selected, clear the selection
+      if (selectedProject === projectToDelete) {
+        onSelectProject(null)
+      }
+      setProjectToDelete(null)
+    } catch (error) {
+      // Error is handled by the mutation, just close the dialog
+      console.error('Failed to delete project:', error)
+      setProjectToDelete(null)
+    }
+  }
+
+  const handleCancelDelete = () => {
+    setProjectToDelete(null)
+  }
+
   const selectedProjectData = projects.find(p => p.name === selectedProject)
 
   return (
@@ -70,28 +102,39 @@ export function ProjectSelector({
             {projects.length > 0 ? (
               <div className="max-h-[300px] overflow-auto">
                 {projects.map(project => (
-                  <button
+                  <div
                     key={project.name}
-                    onClick={() => {
-                      onSelectProject(project.name)
-                      setIsOpen(false)
-                    }}
-                    className={`w-full neo-dropdown-item flex items-center justify-between ${
+                    className={`flex items-center ${
                       project.name === selectedProject
                         ? 'bg-[var(--color-neo-pending)]'
                         : ''
                     }`}
                   >
-                    <span className="flex items-center gap-2">
-                      <FolderOpen size={16} />
-                      {project.name}
-                    </span>
-                    {project.stats.total > 0 && (
-                      <span className="text-sm font-mono">
-                        {project.stats.passing}/{project.stats.total}
+                    <button
+                      onClick={() => {
+                        onSelectProject(project.name)
+                        setIsOpen(false)
+                      }}
+                      className="flex-1 neo-dropdown-item flex items-center justify-between"
+                    >
+                      <span className="flex items-center gap-2">
+                        <FolderOpen size={16} />
+                        {project.name}
                       </span>
-                    )}
-                  </button>
+                      {project.stats.total > 0 && (
+                        <span className="text-sm font-mono">
+                          {project.stats.passing}/{project.stats.total}
+                        </span>
+                      )}
+                    </button>
+                    <button
+                      onClick={(e) => handleDeleteClick(e, project.name)}
+                      className="p-2 mr-2 text-[var(--color-neo-text-secondary)] hover:text-[var(--color-neo-danger)] hover:bg-[var(--color-neo-danger)]/10 transition-colors rounded"
+                      title={`Delete ${project.name}`}
+                    >
+                      <Trash2 size={16} />
+                    </button>
+                  </div>
                 ))}
               </div>
             ) : (
@@ -124,6 +167,19 @@ export function ProjectSelector({
         onClose={() => setShowNewProjectModal(false)}
         onProjectCreated={handleProjectCreated}
       />
+
+      {/* Delete Confirmation Dialog */}
+      <ConfirmDialog
+        isOpen={projectToDelete !== null}
+        title="Delete Project"
+        message={`Are you sure you want to remove "${projectToDelete}" from the registry? This will unregister the project but preserve its files on disk.`}
+        confirmLabel="Delete"
+        cancelLabel="Cancel"
+        variant="danger"
+        isLoading={deleteProject.isPending}
+        onConfirm={handleConfirmDelete}
+        onCancel={handleCancelDelete}
+      />
     </div>
   )
 }