fix(import): preserve SHA algorithms from otpauth URIs

[sean0407]

Summary

otpauth:// import parsed the algorithm query parameter as a name such as SHA512, but EntryStorage.import() expects the numeric enum value. The name failed parseInt() and silently fell back to SHA-1.

algorithm=SHA512 -> "SHA512" -> NaN -> SHA1
algorithm=SHA512 -> "3"      -> 3   -> SHA512

Normalize recognized enum names to their numeric values before the import storage step. Add SHA-256 and SHA-512 regression coverage.

Evidence

• Reproduction URI: otpauth://totp/alice?secret=JBSWY3DPEHPK3PXP&algorithm=SHA512.
• The production import function returned SHA512 before the fix; the storage conversion then selected SHA-1. After the fix it returns 3, which the storage conversion resolves to SHA-512.
• Changed files: src/import.ts, src/test/import.test.ts.
• Checks run: isolated before/after reproduction passed; tsc --noEmit passed; webpack --config webpack.dev.js --mode development compiled successfully; git diff --check passed; patch policy accepted 2 text files and 27 changed lines.

Fixes #1593

Merge Danger

Door: two-way

Blast Radius: localized

Only named algorithm values in otpauth:// imports are normalized; unknown values retain the existing fallback behavior.