[rc1-prep] CODEOWNERS coverage: add directory-scoped rules for all top-level source dirs

[trilamsr]

O7 supporting KPI: CODEOWNERS covers ≥80% of code paths by M12.

Current state. Measured 0% — no top-level source dir
(components/, internal/, module/, install/, scripts/,
tools/, python/, docs/, bench/) has a matching rule in
CODEOWNERS. Existing rules only cover governance
files + /Makefile + /go.mod//go.sum + /.golangci.yml +
/.github/.

Remediation. Add one directory-scoped rule per top-level source
dir, all routing to @TraceCoreAI/core. Lifts measured coverage from
0% → ~95% in one PR. Sub-team splits land later when a second
non-author maintainer joins.

Effort: S (≈10 LOC).

Audit source: docs/v1-rc1-governance-gaps.md §1.

[trilamsr]

Addressed in PR #338 (feat(v1-rc1): 2 detectors + 8 pattern specs + chart NetPol + rc1 audits); closing.