Fix #1489: Type-Unsafe Request Payloads (Missing Pydantic Models)

[sahare-mayur-0071]

Fixes #1489

[utksh1]

Holding off on merging this one. A couple of issues to address first:

1. Encoding/mojibake corruption — the diff introduces broken characters in two existing comments (ΓÇö where an em-dash — used to be) in routes.py. This injects garbage bytes and must be reverted to the original UTF-8.
2. Overlap with other PRs — the type-safety refactor here spans the same target-policy / workflow / credential / session endpoints covered by the more focused #1514, #1515, and #1516 (now merged). Please rebase onto current main and resolve the inevitable conflicts, and consider narrowing scope to whatever isn't already covered.

Once the mojibake is fixed and it's rebased, happy to take another look.

[sahare-mayur-0071]

Thanks for the feedback! I've fixed the mojibake encoding issue in
outes.py and successfully rebased the branch on main to resolve merge conflicts and overlap with the recently merged PRs. It's ready for another look.

[utksh1]

Thanks for this contribution! I've reviewed the proposal and it looks like a valid addition. However, this branch currently has Git merge conflicts with main. Could you please pull the latest changes from upstream, resolve the conflicts, and push the rebased branch so we can continue the review process?