chore: align image workflows and harden workspace startup

[jo-cube]

This PR improves local development and enterprise launch workflows by making image selection consistent, startup more reliable, and common development commands easier to use.

Changes

• Standardize image names as - across Compose, Bake, pulls, builds, and releases.
• Load project-local .env values while preserving shell and explicit flavor overrides.
• Add just pull for published images and just exec for running commands as dev.
• Wait for service readiness during startup and fail immediately when builds or health checks fail.
• Check all enabled browser services through just health.
• Remove the redundant /status endpoint and duplicate image tags.
• Reduce build memory usage by compiling the Rust kernel serially.
• Keep smoke scripts and tests out of runtime image contexts.
• Align enterprise cleanup and launcher behavior with the generic workflow.
• Update documentation, including the Just 1.54+ requirement.
• Add regression coverage for launcher behavior and image resolution.