Add FIPS SHA3-256 and complete selected-file CSV/XLSX reports

[bellabaelfire]

Adds SHA3-256 to the evidence table, System Console, and all report paths for #2. Selected PDF/JPG/other evidence files can now be exported to Hash CSV and a genuine .xlsx workbook; the existing Email CSV remains available. PDF, DOCX and email PDF include the same SHA3-256 digest. Exports reject pending or failed hashes, and a read failure no longer strands later files in the queue.

Because the issue explicitly calls for FIPS 202, this uses pinned MIT js-sha3 rather than CryptoJS.SHA3: CryptoJS documents its Keccak naming mismatch, and js-sha3 exposes SHA3 and Keccak separately. Existing MD5/SHA-256 stay on CryptoJS. Pinned SheetJS CE generates actual XLSX files; the vendored libraries include licenses. Whole-file/main-thread processing remains an inherited limitation.

Validation on Windows, Node 24.19.0 and headless Microsoft Edge:

• 18 Node tests pass, including known answers and Node/OpenSSL comparisons for binary lengths around sponge-block boundaries through 1 MiB.
• A delayed-read regression verifies that Email CSV row numbers, quoted subjects and hashes stay aligned when reads finish out of order; it fails before the follow-up fix and passes afterward.
• Real uploads and six browser downloads pass; CSV/XLSX readback verifies exact digests, filename escaping and selection exclusion. Simulated pending and failed reads verify export guards and queue continuation.
• Independent pypdf and DOCX XML extraction verifies FIPS labels and exact expected hashes in both downloaded PDFs and Word output.
• Desktop and 390px table screenshots reviewed; SHA3 digests wrap in the table. Existing top-links header overflow on narrow screens is outside this change.
• Whitespace checked with git -c core.whitespace=blank-at-eol,blank-at-eof,space-before-tab,cr-at-eol diff --check, preserving the original CRLF HTML file.

Reproduction commands and limitations are in TESTING.md.

Resolves #2.

/claim #2

Bounty listing: https://algora.io/amithmandassociates-oss/hash-report-tool/issues/2

[bellabaelfire]

/claim #2