Standardize local Traverse runtime home for generated binaries and adapter config

[enricopiovesan]

Summary

Define one predictable local Traverse runtime home for generated binaries, fixtures, and adapter configuration overlays.

Why

The OSS pattern extraction note from #108 identified Dapr's self-hosted runtime home pattern as worth adopting in Traverse, but only in a lightweight local-runtime form.

Depends on

None.

Blocked by

None.

Definition of done

• Document the default local Traverse runtime home location and directory layout.
• Cover generated binaries, deterministic fixtures, and adapter configuration overlays.
• Clarify what is runtime-owned versus user-authored.
• Update any relevant smoke/docs paths if needed.

Validation

• the runtime home note exists in the repo
• the documented layout is consistent with checked-in examples or scripts
• PR checks pass

[enricopiovesan]

Implemented the local Traverse runtime-home note and smoke validation on branch codex/issue-110-runtime-home.

What is included:

• docs/local-runtime-home.md with the default .traverse/local/ layout
• explicit ownership boundaries between runtime-owned local state and governed source artifacts
• runtime-home smoke validation through bash scripts/ci/runtime_home_smoke.sh
• cross-links from the executable package and expedition authoring docs

Validation run locally:

• bash scripts/ci/runtime_home_smoke.sh
• bash scripts/ci/repository_checks.sh