Reduce size of bundled assets

[Yadunund]

PR #564 updated our assetization workflows to rely on pixi to pull in vendor packages to skip builds of intrinsic_sdk_cmake deps from source. However since we were still using the same pixi.toml file from quals, copying in the installed pixi environment into the docker container resulted in us copying all deps from quals including lerobot, pytorch, etc which bloated the image sizes.

With this PR asset bundles sizes are reduced from couple gigabytes down to ~300 MB

Key Changes

• Dependency Partitioning (pixi.toml): Split dependencies into default, skill-build, and skill-runtime environments. Moved pixi_env_setup.sh activation under the skill-runtime feature so it executes upon container activation.
• Container Optimization (Dockerfile.skill, Dockerfile.service): Configured builder stages to copy only the target .pixi/envs/skill-runtime directory to the runtime image, stripping out the 3.7 GB build cache (.pixi/build), compilers, and development tools.
• Docs: Cleaned up a Pixi command contradiction in flowstate/README.md.

[trushant05]

Build Performance & Artifact Sizes

Target	Build Time	Bundle Size	Docker Image Size	Cache Status
All 3 Skills	19m 34s	307 MB for each skill bundle	1.2 GB for each skill bundle	Initial build (no cache)
aic_flowstate_ros_bridge	3m 48s	307 MB	1.19 GB	Cached
aic_adapter	3m 19s	1.2 GB	1.19 GB	Cached

@Yadunund could you please verify the aic_adapter bundle size was bloated because there is no compression in the build_aic_adapter.sh script. I pushed a commit with the same and now the bundle size is 338 MB.

The PR LGTM after that verification from your end.