Add no-write SEC fundamentals preview

[YuzeJ21]

What changed

• reveal existing lower-case screener context in the single-stock report
• add a capped, official-SEC-only annual fundamentals comparison for up to five explicit tickers
• keep the comparison inspection-only: no cache, import, canonical, readiness, or output writes and no apply path
• report exact annual filing context, source references, source-rights classification, schema risk, and per-field blockers
• document the workflow and its fail-closed boundary in the public README

Why

Canonical fundamentals can be stale or mix reporting periods. Reviewers needed a safe way to compare current SEC annual facts before any source-rights expansion, schema decision, or canonical apply. The report renderer also expected display-case screener keys while real payloads used lower-case keys.

Product impact

A reviewer can inspect source-backed annual facts for an explicit cohort without activating product readiness. Only direct fields already allowed by the registered SEC scope can become future owner-review candidates. Derived, out-of-scope, mixed-period, malformed, and missing evidence remains blocked.

Verification

• renderer-focused suite: 1,195 passed
• SEC focused contracts: 36 passed
• full affected SEC/import/report/launcher slice: 254 passed
• public documentation/wording/guardrail/launcher slice: 204 passed
• independent current-byte review: no remaining Critical or Important findings
• live AAPL/AMZN/GOOG result: inspection_only, repository_writes=[], canonical_apply_authorized=false
• all tracked data/output hashes and ignored local SEC/import inputs remained unchanged

Boundaries

This PR does not apply data, expand registered commercial field rights, refresh readiness, add generated artifacts, publish a hosted app, or provide investment recommendations.