0.8.1 — Documentation: feature-list README, namespace imports, fingerprint design record

Documentation only. No runtime change; the emitted declarations differ in
their comments alone.

• README: opens with a description of the utility and a feature list; adds a
  "Why not just…" section, an "On the agent's side" section, and a Limits
  table; shows both reports of one failure side by side from a real run.
• Every snippet and example uses import * as AppEx from 'application-exception';
  AGENTS.md rule 0 records the convention. Named imports are unchanged.
• New docs/design/public-fingerprint.md holds the public-fingerprint threat
  model; README, recipes, and AGENTS.md link to it instead of repeating it.
• API card: four new task rows (retry, escalate, thrown primitive, untrusted
  value), an output line on every example, and a description of what each
  PublicReportCorjOptions key does.
• errors.md: a code-to-fix table at the top; APPEX_INVALID_TRUST_REALM now
  names isTrustedException, the function that takes a realm.
• AGENTS.md rule 10 split into one fact per rule; recipe prose trimmed to each
  task; decoder limits and foreign-ID adoption notes deduplicated.
• Repository: process documents removed; docs:check type-checks
  examples/*.ts; dev dependencies moved to Jest 30.

npm: https://www.npmjs.com/package/application-exception/v/0.8.1