Loki Mode v7.48.0

Fix: shellcheck SC2120 on spec-interrogation.sh (v7.47.0 workflow red)

• The v7.47.0 spec-interrogation module tripped SC2120 (optional-arg warning) on
  the GH shellcheck runner (a stricter shellcheck version than the local one).
  Added a targeted # shellcheck disable=SC2120 with rationale (the [path]
  argument is optional by design). Tests workflow is green again.

Enterprise: telemetry is now opt-in (P3-2)

• Telemetry and diagnostics no longer egress by default. Nothing is collected or
  sent unless explicitly enabled (LOKI_TELEMETRY=on or loki telemetry on).
  A default install, including air-gapped / GDPR / FedRAMP environments, sends us
  nothing. All prior opt-out flags still work and always win. Documented the exact
  (PII-free) data inventory in docs/PRIVACY.md.

Verification depth: semantic test-authenticity detector (P1-3)

• New tests/detect-semantic-test-problems.sh catches fake tests that the
  existing mock/mutation detectors miss: assertions that echo a literal through a
  variable, assertions on a mock's own return value, and net-deleted assertions
  across commits. Conservative by design (never flags a genuine computed
  assertion like expect(add(2,2)).toBe(4)). Available now; wiring it as a
  blocking gate is a tracked follow-up.

Verification depth: real coverage measurement + run manifest (P0-1 Fix A, P3-5)

• The test gate can now actually MEASURE coverage per language (vitest, jest,
  pytest-cov, go, cargo-llvm-cov) and records it honestly in
  .loki/quality/coverage.json. Measurement is opt-in (it re-runs the suite
  instrumented, so it is off by default to keep autonomous iterations fast): set
  LOKI_COVERAGE_GATE=1 to measure-and-record (warn if below LOKI_MIN_COVERAGE,
  default 80), or LOKI_ENFORCE_COVERAGE=1 to also block a below-threshold-and-
  measurable result. When no coverage tool is present the gate passes through and
  records "not measured" (never fabricates a number).
• Every run now emits .loki/loki-run.json, a bill-of-materials (spec path+hash,
  model tier used, provider, loki + tool versions, evidence hashes, git SHAs,
  outcome) so a run is auditable and reproducible. Best-effort, never aborts a run.

Each stream built in an isolated worktree, council-reviewed, local-ci green.