[teamhimeh]

Add pr-dependencies.md to plan contribution of the fork's five JNI fixes to swiftlang/swift-java. The Mermaid graph identifies fixes by their qoncept/swift-java PR numbers (#1–#5), matching how the work is tracked in origin, while its arrows represent prerequisites for upstream submission and merging.

Protocol extension requirement classification (origin #2) precedes requirement naming (origin #3); the other fixes can target upstream main independently. Record origin PR links, the existing upstream PR #938, source branches and commits, dependency rationale, and submission order. Keep upstream PR numbers and statuses distinct from origin tracking and merge status.

Validation:

• Checked origin PR numbers against their titles and source branches.
• Checked source patches and upstream PR status against upstream main at 301e3da.
• Confirmed each of the four independent patches passes git apply --check on that baseline.
• Confirmed the naming patch fails to apply alone and passes after the protocol extension patch.
• git diff --cached --check passed.

Documentation only; no runtime code changes.