chore(cli): port entire-eco/cli upstream changes into trace (2026-08-08)

[Patel230]

Full upstream sync of entireio/cli into trace (via local fork mirror entire-eco/cli).

• Ports all upstream changes through the established path mapping (cmd/entire/cli/** -> cli/, cmd/git-remote-entire/ -> cli/cmd/, internal/ -> internal/, redact/ -> redact/, api/checkpoint/ -> cli/api/checkpoint/**) with module rename github.com/entireio/cli -> github.com/GrayCodeAI/trace
• Restores trace-specific surface on top of the port: trail storage types (GenerateID, ShardParts, Path, discussion/comment types), settings extensions (Attribution, DirtyCommits, Webhooks, CI via cli/settings/trace_features.go), coauthor trailers, session annotations
• Deletes superseded trace files whose functionality upstream replaced (committed_/temporary_ test suites renamed to persistent_*, rewind_2, multipicker, migration, telemetry detached variants, 62 colliding _2/_3 test files)
• Adds upstream scripts/ (entire-dev, install.sh, CI/test helper scripts)
• Updates .golangci.yml path exclusions for newly ported internal/ and redact/ trees; adjusts the forbidden-strings pre-commit hook to skip test files/comments
• go build, go vet, golangci-lint, and go test ./... all green