fix(teams): propagate CLAUDE_CONFIG_DIR to tmux session for agent teammates

When CCS launches Claude with CLAUDE_CONFIG_DIR pointing to the isolated
instance path, agent team teammates spawned via tmux split-window don't
inherit it because tmux creates new panes from its own session environment.
This causes teammates to use ~/.claude/ instead of ~/.ccs/instances/{profile}/,
creating a split-brain in shared state (tasks, teams, mailbox).

Sets key CCS env vars in the tmux session environment via `tmux setenv` so
all new panes inherit the correct config directory.

src/utils/shell-executor.ts

@@ -4,7 +4,7 @@
  * Cross-platform shell execution utilities for CCS.
  */
 
-import { spawn, ChildProcess } from 'child_process';
+import { spawn, ChildProcess, execSync } from 'child_process';
 import { ErrorManager } from './error-manager';
 import { getWebSearchHookEnv } from './websearch-manager';
 
@@ -82,6 +82,21 @@ export function execClaude(
     ? { ...baseEnv, ...envVars, ...webSearchEnv }
     : { ...baseEnv, ...webSearchEnv };
 
+  // propagate key env vars to tmux session so agent team teammates
+  // (spawned via tmux split-window) inherit the correct config dir
+  if (process.env.TMUX && envVars) {
+    const tmuxPropagateVars = ['CLAUDE_CONFIG_DIR', 'CCS_PROFILE_TYPE', 'CCS_WEBSEARCH_SKIP'];
+    for (const key of tmuxPropagateVars) {
+      if (envVars[key]) {
+        try {
+          execSync(`tmux setenv ${key} ${JSON.stringify(envVars[key])}`, { stdio: 'ignore' });
+        } catch {
+          // tmux setenv can fail if not in a tmux session; safe to ignore
+        }
+      }
+    }
+  }
+
   let child: ChildProcess;
   if (needsShell) {
     // When shell needed: concatenate into string to avoid DEP0190 warning