fix(server): encode V2 response IntegrityIds

[gijzelaerr]

Summary

• append the current per-client read or write IntegrityId to every established-session V2 response
• preserve the legacy V1 response layout
• preserve the current server's optional TCP-reset behavior after symbolic reads
• cover read/write counter selection and sequential V2 TLS operations

The branch now includes current master through a merge commit; its previous conflicts are resolved without rewriting history.

Verification

• uv run --frozen --extra test --extra s7commplus pytest -q (1779 passed, 82 skipped)
• focused V2/TLS/server tests (124 passed)
• uv run --frozen pre-commit run --all-files
• uv build --no-sources

Fixes #802

[gijzelaerr]

@bvanelli Could you review the V2 emulator response behavior here, particularly selecting the read/write counter and appending the IntegrityId without changing the V1 payload layout? The conflict repair also preserves the newer symbolic-read TCP-reset emulation.

The refreshed head passes 1,779 tests, the complete pre-commit suite, and the package build.

[gijzelaerr]

@ale-rinaldi you have detailed V2/TLS observations from the 1507S and 1211C. Could you review the server response layout here against your real-PLC captures or traces, particularly whether the read/write IntegrityId selection and appended counter match V2 responses without changing the V1 payload shape?\n\nThis is primarily a capture/protocol review; it does not require exposing project data or pointing a real PLC at the emulator.

[bvanelli]

Here, it appends the integrity_id to every function. In theory, this could also apply to _build_error_response and _handle_init_ssl. I'm not sure those use need the integrity id.