[REV-2383] Scope cloud agent launches to selected team

[warp-agent-staging]

Description

Scope cloud agent launches to the selected team by threading RequestTeamScope through AIClient::spawn_agent, spawn_task, local-to-cloud handoff, and the CLI, GUI, and TUI callers. The HTTP transport applies X-Warp-Team-Uid only for selected-team scope, while retry and deferred launch paths retain the initiating scope.

This PR is stacked on #15805 and includes its corrected --personal environment handling.

Linked Issue

• REV-2383
• Originating Slack thread
• Parent PR: [REV-2383] Scope Oz environment selection to a team #15805
• The linked issue is labeled ready-to-spec or ready-to-implement (the migration tracker is currently in review).

Testing

• /workspace/warp/script/format --check
• /workspace/warp/script/check_no_inline_test_modules
• cargo check -p warp_tui
• Focused transport-header and GitHub-auth retry regression tests
• All 20 ai::ambient_agents::spawn::tests
• All 19 ai::blocklist::handoff::pipeline::tests
• ai::agent_sdk::common::tests for the corrected parent scope behavior
• cargo clippy -p warp_tui -- -D warnings
• cargo clippy -p warp --lib --tests -- -D warnings

The full presubmit passed formatting, inline-test checks, Clippy, clang-format, factory-file validation, and WGSL formatting before full workspace test compilation exhausted the sandbox target volume (No space left on device). Post-parent-refresh focused checks and Clippy passed using an alternate Cargo target directory.

• I have manually tested my changes locally with ./script/run (automated verification only, per request).

Agent Mode

• Warp Agent Mode - This PR was created via Warp's AI Agent Mode

CHANGELOG-NONE

[warp-agent-staging]

This PR was generated with Warp.

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