* fix(core,errors): classify SDK encryption failures as RUNTIME_ERROR
SDK-level AES-GCM encrypt/decrypt failures are never the user's fault,
but the run-failure classifier was tagging them as USER_ERROR because
the native Web Crypto OperationError (most commonly raised by
AESCipherJob.onDone on GCM auth-tag mismatch) does not match any
RUNTIME_ERROR_CHECKS entry.
Introduce a new RuntimeDecryptionError (subclass of WorkflowRuntimeError)
that the encryption module throws when subtle.encrypt/subtle.decrypt
fails, with the original DOMException as cause plus diagnostic context
(operation, byteLength, printable/hex format prefix of the input
header). classifyRunError now picks it up via RUNTIME_ERROR_CHECKS, so
these failures surface as RUNTIME_ERROR with a proper named class for
dashboards and triage.
* Trim changeset description to one sentence
* Trim historical-context comments
* docs: add runtime-decryption-failed troubleshooting page (v4 + v5)
* fix(core): round-trip RuntimeDecryptionError context, fix formatPrefix, propagate through serialization wrappers
Addresses review feedback on #2145:
- Add a RuntimeDecryptionError reducer/reviver (+ SerializableSpecial
entry + globalThis registration) so its `context` (operation,
byteLength, formatPrefix) survives the dehydrate/hydrate run-error
round trip instead of being dropped by the generic Error reducer.
- Stop capturing `formatPrefix` in the low-level encryption layer, which
only sees the stripped AES payload (nonce bytes), not the outer `encr`
marker. The serialization layer now attaches the real envelope prefix.
- Rethrow RuntimeDecryptionError unchanged from the serialize/dehydrate
catch blocks instead of reframing it as a SerializationError, so an
encryption failure during dehydration stays a RUNTIME_ERROR rather than
being misclassified as USER_ERROR.
* fix(core): enrich stream decrypt errors with envelope prefix + fix lint
- Mirror the catch/enrich/rethrow block from serialization/encryption.ts
around the stream-path aesGcmDecrypt() call so auth-tag failures on
encrypted stream frames also carry context.formatPrefix = 'encr'
(addresses review feedback). Add a tampered-frame test.
- Fix all auto-fixable Biome lint findings in the touched files
(template literals, useless try/catch wrappers, optional chaining,
non-null assertions).