feat: unified Claude API key and profile system with z.AI, MiniMax, OpenRouter support (#600)

* feat: add Claude API provider profiles for alternative endpoints

Add support for managing multiple Claude-compatible API endpoints
(z.AI GLM, AWS Bedrock, etc.) through provider profiles in settings.

Features:
- New ClaudeApiProfile type with base URL, API key, model mappings
- Pre-configured z.AI GLM template with correct model names
- Profile selector in Settings > Claude > API Profiles
- Clean switching between profiles and direct Anthropic API
- Immediate persistence to prevent data loss on restart

Profile support added to all execution paths:
- Agent service (chat)
- Ideation service
- Auto-mode service (feature agents, enhancements)
- Simple query service (title generation, descriptions, etc.)
- Backlog planning, commit messages, spec generation
- GitHub issue validation, suggestions

Environment variables set when profile is active:
- ANTHROPIC_BASE_URL, ANTHROPIC_AUTH_TOKEN/API_KEY
- ANTHROPIC_DEFAULT_HAIKU/SONNET/OPUS_MODEL
- API_TIMEOUT_MS, CLAUDE_CODE_DISABLE_NONESSENTIAL_TRAFFIC

apps/server/src/services/agent-service.ts

@@ -29,6 +29,7 @@ import {
   getSkillsConfiguration,
   getSubagentsConfiguration,
   getCustomSubagents,
+  getActiveClaudeApiProfile,
 } from '../lib/settings-helpers.js';
 
 interface Message {
@@ -274,6 +275,13 @@ export class AgentService {
           ? await getCustomSubagents(this.settingsService, effectiveWorkDir)
           : undefined;
 
+      // Get active Claude API profile for alternative endpoint configuration
+      const { profile: claudeApiProfile, credentials } = await getActiveClaudeApiProfile(
+        this.settingsService,
+        '[AgentService]',
+        effectiveWorkDir
+      );
+
       // Load project context files (CLAUDE.md, CODE_QUALITY.md, etc.) and memory files
       // Use the user's message as task context for smart memory selection
       const contextResult = await loadContextFiles({
@@ -378,6 +386,8 @@ export class AgentService {
         agents: customSubagents, // Pass custom subagents for task delegation
         thinkingLevel: effectiveThinkingLevel, // Pass thinking level for Claude models
         reasoningEffort: effectiveReasoningEffort, // Pass reasoning effort for Codex models
+        claudeApiProfile, // Pass active Claude API profile for alternative endpoint configuration
+        credentials, // Pass credentials for resolving 'credentials' apiKeySource
       };
 
       // Build prompt content with images