chore: bump mopro-ffi/cli to 0.3.6, pin template to fix Kotlin CI

[moven0831]

Summary

• Bumps mopro-ffi and mopro-cli from 0.3.4 → 0.3.6 (skipping the poisoned 0.3.5 slot on crates.io).
• Pins the mopro init template (cli/src/init/write_toml.rs) to mopro-ffi = "=0.3.6" (exact-version pin) so a future bad release in the 0.3.x range cannot silently break the template again.

Why

Every cli_template_tests matrix job on main has been red since 2026-03-16 with:

…/uniffi/mopro_example_*/mopro_example_*.kt:83:46: warning: redundant call of conversion method.
this.data?.getByteBuffer(0, this.len.toLong())?.also {
error: warnings found and -Werror specified
test uniffi_foreign_language_testcase_test_ffi_hello_world_kts ... FAILED

Root cause:

1. The workspace already pins uniffi = "=0.31.0" (PR chore: update dependencies and refactor uniffi integration #658). UniFFI 0.31 fixed the redundant .toLong() in RustBufferTemplate.kt:50 (0.29 emits this.len.toLong(), 0.31 emits this.len).
2. The template generated by mopro init depends on mopro-ffi = "0.3.4" (cli/src/init/write_toml.rs:19,35,43). Cargo resolves that to the latest published 0.3.x on crates.io, which is mopro-ffi 0.3.5 — released on 2026-03-08 from the origin/v0.3.5 branch (based on a pre-chore: update dependencies and refactor uniffi integration #658 main), still locked to uniffi =0.29.0. Verified via the crates.io dependency API.
3. UniFFI's bindgen-tests feature runs kotlinc -Werror. A recent GitHub Actions runner-image refresh bumped kotlinc to a release that flags the redundant .toLong() as a warning — which becomes a fatal error under -Werror.

Regression bisect confirms the break is environmental, not source: last green run was ef60c27 (2026-03-03), first red run was 6e59bac (2026-03-16), and the only intermediate commit on main is a docs-only blog post (#702).

cli_build_android (gradle) is unaffected; only the Kotlin UniFFI foreign-language test in cli_template_tests fails. The Swift sibling test (…_test_ffi_hello_world_swift) passes.

Publishing (post-merge)

There's no release workflow in this repo; previous releases were manual. After merge:

git checkout main && git pull
cargo publish -p mopro-ffi
cargo publish -p mopro-cli
git tag v0.3.6 && git push --tags

Then verify on crates.io that mopro-ffi 0.3.6 lists uniffi 0.31.x under Dependencies.

⚠️ Until mopro-ffi 0.3.6 is on crates.io, this PR's own CI will fail to resolve the new =0.3.6 pin in the template. The fix only goes green on main once the publish step above completes and CI is re-run there.

Out of scope

cli/src/bindgen.rs:166-167 still references a stale mopro-ffi = { version = "0.3.2", features = ["uniffi"] } literal that no longer matches what write_toml.rs emits — this silently breaks the witnesscalc-adapter path. Unrelated to the Kotlin CI failure; flagging here so it doesn't get lost.

Test plan

• CI: cli_template_tests (5 adapters × 2 OSes) goes green on main after mopro-ffi 0.3.6 is published.
• Manual: on a clean machine, cargo install --path cli && mopro init testproj && cd testproj && cargo test --all --all-features succeeds end-to-end.
• Crates.io: curl -s https://crates.io/api/v1/crates/mopro-ffi/0.3.6/dependencies shows uniffi 0.31.x, not =0.29.0.

🤖 Generated with Claude Code

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