Add status command template

[AlwaysHC]

Summary

• Add a read-only /speckit.status command template for all-spec workflow status reports
• Surface the generated speckit-status skill/command in CLI descriptions, Claude argument hints, and README docs
• Update integration inventory tests for the new command

Tests

• uv run --extra test pytest tests\integrations\test_integration_codex.py tests\integrations\test_integration_amp.py tests\integrations\test_integration_gemini.py tests\integrations\test_integration_goose.py tests\integrations\test_integration_generic.py tests\integrations\test_integration_copilot.py
• uv run --extra test pytest tests\integrations\test_integration_claude.py

[mnriem]

Please review our community extensions or deliver this as a community extension. Thank you!