[Task] v5.6 upload/config view, cosmetic changes, and label bump

[SeaCelo]

Last sub-issue, lands after the others. Catches everything left over: UploadRoute.py changes, the Config view rework, cosmetic noise, and the version label bump.

What's in scope:

• UploadRoute.py: hand-merge upstream's signature change (updateViewDefintions(casename, genData)), the new updateGenData function, the new 5.6 upgrade branch. Hand-verify each upgrade-from-old-version branch. Preserve MUIOGO's request validation (PR fix: add input validation to critical API routes to prevent 500 on mi… #79) and OSError handling (PR fix: replace bare raise OSError with structured JSON 500 responses #90)
• Config.js, Config.html, Config.Model.js: take upstream's view rework, drop the console.log re-adds
• RY*.html and RY*.Model.js: take the uniform 6-line cosmetic touches
• osy.css: take upstream cosmetic changes except the floating live-log console UI (#openLogBtn, #logWidget) — that's tied to a static-tree app.log and is rejected per UPSTREAM_SYNC.md
• model.v.5.4.txt: take upstream's whitespace normalization (no functional changes)
• WebAPP/References/smartadmin/img/osemosys.gif: take upstream's replacement
• docs/source/contributing/support.rst: keep MUIOGO's GitHub Discussions pointer
• Versions.html: hand-merge — keep MUIOGO's 5.5 entry, add upstream's 5.6 entry, add MUIOGO's own 5.6 sync notes describing what we did
• WebAPP/index.html and Navbar.html: title and version label bump from "MUIO 5.5" to "MUIO 5.6"

Reject as-is per UPSTREAM_SYNC.md:

• WebAPP/App/Controller/DataFile - Copy.js, DataFile - Copy.html, DataFile.Model - Copy.js (dormant editor leftovers)
• WebAPP/app.log.2026-04-26 (log under static web tree)
• FileClassCompressed.py (still dormant)

Done when:

• branch base: feature/v56-ui-sync
• this is the last sub-PR before the feature branch merges to main
• WebAPP/index.html and Versions.html reflect "MUIO 5.6"
• demo case opens and runs end-to-end

Notes:

• branch base: feature/v56-ui-sync (not main)
• lands last — version labels should reflect "MUIO 5.6" only after the rest of the work is in
• the Versions.html changelog content is a maintainer-flavored task — author should propose draft text in the PR description for maintainer review

Related: #457, docs/UPSTREAM_SYNC.md