[build-runtime] Separate Build/Version/Runtime Supporting Fixes

[kangeunchan]

Enhancement Description

• One-line description (release-note style): Isolate supporting build/version/runtime fixes needed to keep Cosmos deploy workflow operational and reviewable.
• Scope type: Tooling and supporting runtime fixes outside core Cosmos plugin scope

Background

Alongside Cosmos plugin completion, several supporting fixes were required in build/version/runtime paths.
These changes are useful but make the main Cosmos completion issue too broad.

This issue tracks:

• Supporting fixes separated from core plugin completion scope

Scope

• Fix build output flow (go install -o misuse -> go build outputs)
  • Files: Makefile
• Enforce semver-safe version migration target resolution
  • Files: Makefile, cmd/devnet-builder/main.go
• Normalize runtime docker start command home handling
  • Files: internal/daemon/runtime/docker.go, internal/daemon/runtime/docker_test.go
• Add small local artifact ignore cleanups
  • Files: .gitignore
• Keep provider testnet default alignment changes separate for focused review
  • Files: docs/plugins/cosmos-plugin.md, internal/plugin/cosmos/genesis.go

Non-Goals

• Reworking Cosmos plugin core behavior
• Snapshot engine redesign
• Large architecture refactor

Risks and Open Questions

• Build/version fixes can affect all users, not only Cosmos path
• Migration behavior needs compatibility confirmation with existing homes
• Runtime home normalization needs cross-platform/path edge-case validation

Validation Plan

Unit and Integration Checks

• go test ./... in environment where full suite is runnable
• Focused tests around version migration and runtime command assembly

End-to-End Checks

• make build succeeds and produces expected binaries
• Existing home migration from old version completes without regression
• Deploy/start commands continue to work with normalized runtime path handling

Evidence Required in Issue Updates

• Build output log snippets
• Migration success/failure behavior logs before/after
• Runtime command assembly examples before/after normalization

Acceptance Criteria

• Build flow no longer depends on invalid go install -o usage
• Version migration target resolution is semver-safe and deterministic
• Runtime home normalization avoids path mismatch regressions
• Supporting fixes stay reviewable outside Cosmos core scope

Deliverables

• Pushed build/runtime/version support fix branches for review
• Regression notes for cross-path impact

Branch / PR

• Branch: fix/build-go-build-output
• Branch: fix/version-semver-migration
• Branch: fix/runtime-home-flag
• Branch: chore/local-artifacts-ignore
• Branch: fix/cosmos-provider-testnet-defaults