feat(provider-adapter): implement multi-provider abstraction layer (Phase 1)

Add provider types, registry, capabilities, and message adapter registry.
Rename sdk-messages→claude-messages, agent-runner→claude-runner,
ClaudeSession→AgentSession. Update Rust AgentQueryOptions with provider
and provider_config fields. Capability-driven AgentPane rendering.

v2/sidecar/agent-runner.ts

@@ -1,215 +0,0 @@
-// Agent Runner — Node.js sidecar entry point
-// Spawned by Rust backend, communicates via stdio NDJSON
-// Uses @anthropic-ai/claude-agent-sdk for proper Claude session management
-
-import { stdin, stdout, stderr } from 'process';
-import { createInterface } from 'readline';
-import { execSync } from 'child_process';
-import { existsSync } from 'fs';
-import { join } from 'path';
-import { homedir } from 'os';
-import { query, type Query } from '@anthropic-ai/claude-agent-sdk';
-
-const rl = createInterface({ input: stdin });
-
-// Active agent sessions keyed by session ID
-const sessions = new Map<string, { query: Query; controller: AbortController }>();
-
-function send(msg: Record<string, unknown>) {
-  stdout.write(JSON.stringify(msg) + '\n');
-}
-
-function log(message: string) {
-  stderr.write(`[sidecar] ${message}\n`);
-}
-
-rl.on('line', (line: string) => {
-  try {
-    const msg = JSON.parse(line);
-    handleMessage(msg).catch((err: unknown) => {
-      log(`Unhandled error in message handler: ${err}`);
-    });
-  } catch {
-    log(`Invalid JSON: ${line}`);
-  }
-});
-
-interface QueryMessage {
-  type: 'query';
-  sessionId: string;
-  prompt: string;
-  cwd?: string;
-  maxTurns?: number;
-  maxBudgetUsd?: number;
-  resumeSessionId?: string;
-  permissionMode?: string;
-  settingSources?: string[];
-  systemPrompt?: string;
-  model?: string;
-  claudeConfigDir?: string;
-  additionalDirectories?: string[];
-}
-
-interface StopMessage {
-  type: 'stop';
-  sessionId: string;
-}
-
-async function handleMessage(msg: Record<string, unknown>) {
-  switch (msg.type) {
-    case 'ping':
-      send({ type: 'pong' });
-      break;
-    case 'query':
-      await handleQuery(msg as unknown as QueryMessage);
-      break;
-    case 'stop':
-      handleStop(msg as unknown as StopMessage);
-      break;
-    default:
-      send({ type: 'error', message: `Unknown message type: ${msg.type}` });
-  }
-}
-
-async function handleQuery(msg: QueryMessage) {
-  const { sessionId, prompt, cwd, maxTurns, maxBudgetUsd, resumeSessionId, permissionMode, settingSources, systemPrompt, model, claudeConfigDir, additionalDirectories } = msg;
-
-  if (sessions.has(sessionId)) {
-    send({ type: 'error', sessionId, message: 'Session already running' });
-    return;
-  }
-
-  log(`Starting agent session ${sessionId} via SDK`);
-
-  const controller = new AbortController();
-
-  // Strip CLAUDE* and ANTHROPIC_* env vars to prevent nesting detection by the spawned CLI.
-  // Whitelist CLAUDE_CODE_EXPERIMENTAL_* so feature flags (e.g. agent teams) pass through.
-  const cleanEnv: Record<string, string | undefined> = {};
-  for (const [key, value] of Object.entries(process.env)) {
-    if (key.startsWith('CLAUDE_CODE_EXPERIMENTAL_')) {
-      cleanEnv[key] = value;
-    } else if (!key.startsWith('CLAUDE') && !key.startsWith('ANTHROPIC_')) {
-      cleanEnv[key] = value;
-    }
-  }
-  // Override CLAUDE_CONFIG_DIR for multi-account support
-  if (claudeConfigDir) {
-    cleanEnv['CLAUDE_CONFIG_DIR'] = claudeConfigDir;
-  }
-
-  try {
-    if (!claudePath) {
-      send({ type: 'agent_error', sessionId, message: 'Claude CLI not found. Install Claude Code first.' });
-      return;
-    }
-
-    const q = query({
-      prompt,
-      options: {
-        pathToClaudeCodeExecutable: claudePath,
-        abortController: controller,
-        cwd: cwd || process.cwd(),
-        env: cleanEnv,
-        maxTurns: maxTurns ?? undefined,
-        maxBudgetUsd: maxBudgetUsd ?? undefined,
-        resume: resumeSessionId ?? undefined,
-        allowedTools: [
-          'Bash', 'Read', 'Write', 'Edit', 'Glob', 'Grep',
-          'WebSearch', 'WebFetch', 'TodoWrite', 'NotebookEdit',
-        ],
-        permissionMode: (permissionMode ?? 'bypassPermissions') as 'bypassPermissions' | 'default',
-        allowDangerouslySkipPermissions: (permissionMode ?? 'bypassPermissions') === 'bypassPermissions',
-        settingSources: settingSources ?? ['user', 'project'],
-        systemPrompt: systemPrompt
-          ? systemPrompt
-          : { type: 'preset' as const, preset: 'claude_code' as const },
-        model: model ?? undefined,
-        additionalDirectories: additionalDirectories ?? undefined,
-      },
-    });
-
-    sessions.set(sessionId, { query: q, controller });
-    send({ type: 'agent_started', sessionId });
-
-    for await (const message of q) {
-      // Forward SDK messages as-is — they use the same format as CLI stream-json
-      const sdkMsg = message as Record<string, unknown>;
-      send({
-        type: 'agent_event',
-        sessionId,
-        event: sdkMsg,
-      });
-    }
-
-    // Session completed normally
-    sessions.delete(sessionId);
-    send({
-      type: 'agent_stopped',
-      sessionId,
-      exitCode: 0,
-      signal: null,
-    });
-  } catch (err: unknown) {
-    sessions.delete(sessionId);
-    const errMsg = err instanceof Error ? err.message : String(err);
-
-    if (controller.signal.aborted) {
-      log(`Agent session ${sessionId} aborted`);
-      send({
-        type: 'agent_stopped',
-        sessionId,
-        exitCode: null,
-        signal: 'SIGTERM',
-      });
-    } else {
-      log(`Agent session ${sessionId} error: ${errMsg}`);
-      send({
-        type: 'agent_error',
-        sessionId,
-        message: errMsg,
-      });
-    }
-  }
-}
-
-function handleStop(msg: StopMessage) {
-  const { sessionId } = msg;
-  const session = sessions.get(sessionId);
-  if (!session) {
-    send({ type: 'error', sessionId, message: 'Session not found' });
-    return;
-  }
-
-  log(`Stopping agent session ${sessionId}`);
-  session.controller.abort();
-}
-
-function findClaudeCli(): string | undefined {
-  // Check common locations
-  const candidates = [
-    join(homedir(), '.local', 'bin', 'claude'),
-    join(homedir(), '.claude', 'local', 'claude'),
-    '/usr/local/bin/claude',
-    '/usr/bin/claude',
-  ];
-  for (const p of candidates) {
-    if (existsSync(p)) return p;
-  }
-  // Fall back to which/where
-  try {
-    return execSync('which claude 2>/dev/null || where claude 2>nul', { encoding: 'utf-8' }).trim().split('\n')[0];
-  } catch {
-    return undefined;
-  }
-}
-
-const claudePath = findClaudeCli();
-if (claudePath) {
-  log(`Found Claude CLI at ${claudePath}`);
-} else {
-  log('WARNING: Claude CLI not found — agent sessions will fail');
-}
-
-log('Sidecar started');
-send({ type: 'ready' });