fix(cli): honor AGENT_BROWSER_DEFAULT_TIMEOUT env var for wait commands (#1153)

* fix(cli): honor AGENT_BROWSER_DEFAULT_TIMEOUT env var for wait commands

The `AGENT_BROWSER_DEFAULT_TIMEOUT` environment variable was being ignored by CLI wait commands, causing them to use hardcoded 30-second timeouts instead of the configured default.

## Changes Made

- **Centralized timeout injection**: Modified `parse_command()` to automatically inject `flags.default_timeout` into any wait-family command that doesn't already have an explicit `--timeout` flag
- **Environment variable parsing**: Added `default_timeout` field to `Flags` struct that reads from `AGENT_BROWSER_DEFAULT_TIMEOUT` env var
- **Daemon propagation**: Updated daemon spawning to pass through the default timeout via environment variables
- **Unified timeout handling**: Added `timeout_ms()` helper method in `DaemonState` that all wait handlers now use instead of scattered `unwrap_or()` calls
- **Comprehensive test coverage**: Added 10 regression tests covering all wait command variants and edge cases

## Implementation Details

The fix uses a two-stage approach:
1. CLI parses the env var and injects timeout values into command JSON for any `wait*` action
2. Daemon reads the env var and provides a centralized fallback via `timeout_ms()` helper

This ensures new wait variants automatically inherit the default timeout without requiring per-variant wiring.

Fixes #1147

* fix: preserve 30s default timeout for backward compatibility

The default_timeout_ms fallback was set to 25_000ms, which silently
changes the existing 30_000ms behavior for users who haven't set
AGENT_BROWSER_DEFAULT_TIMEOUT. Restore the original 30s default.

---------

Co-authored-by: ctate <366502+ctate@users.noreply.github.com>

cli/src/flags.rs

@@ -300,6 +300,7 @@ pub struct Flags {
     pub screenshot_quality: Option<u32>,
     pub screenshot_format: Option<String>,
     pub idle_timeout: Option<String>, // Canonical milliseconds string for AGENT_BROWSER_IDLE_TIMEOUT_MS
+    pub default_timeout: Option<u64>, // AGENT_BROWSER_DEFAULT_TIMEOUT in ms
     pub no_auto_dialog: bool,
 
     // Track which launch-time options were explicitly passed via CLI
@@ -432,6 +433,9 @@ pub fn parse_flags(args: &[String]) -> Flags {
             "AGENT_BROWSER_IDLE_TIMEOUT_MS",
         )
         .or(config.idle_timeout),
+        default_timeout: env::var("AGENT_BROWSER_DEFAULT_TIMEOUT")
+            .ok()
+            .and_then(|s| s.parse::<u64>().ok()),
         no_auto_dialog: env_var_is_truthy("AGENT_BROWSER_NO_AUTO_DIALOG")
             || config.no_auto_dialog.unwrap_or(false),
         cli_executable_path: false,