✨ Add replaceable Client drivers and stable device IDs

[burgholzer]

🤖 AI text below 🤖

Description

Define a replaceable Client-driver ABI and stable client-visible device IDs for QDMI 1.4. This PR is based directly on develop; it has no batching, payload-capability, or metadata-cleanup prerequisite.

The contract adds:

• A pure QDMI_driver_get_client_abi_version query, generated from the QDMI version, and exported Client Interface symbols.
• Lazy, transactional, retryable driver initialization in QDMI_session_alloc.
• Mandatory stable Client Interface device IDs, supplied by the driver when absent from the device.
• Explicit runtime IDs in the example configuration.

IDs are opaque, nonempty, immutable per handle, unique within a session, and stable across equivalent sessions and process restarts while the logical resource exists. They are not display names, endpoints, credentials, library versions, symbol prefixes, or CMake properties.

The existing format enum and job API remain unchanged. MQT Core still owns its private discovery/configuration extension; standardizing that extension is QDMI v2 work, not part of this PR.

Validation

• Independent release configure/build and CTest: 85 passed, 18 expected read-only skips, no failures.
• uvx prek run -a: passed.
• Replayed commits are signed; the published head was verified.
• Fresh hosted CI is pending. Previous stack coverage and CI results do not describe this head.

AI assistance: Codex separated the driver changes, retained only the version helpers needed for the ABI, and ran local validation.

Checklist

• The pull request only contains commits that are focused and relevant to this change.
• I have added appropriate tests that cover the new/changed functionality.
• I have updated the documentation to reflect these changes.
• I have added entries to the changelog for any noteworthy additions, changes, fixes, or removals.
• I have added migration instructions to the upgrade guide (if needed).
• The changes follow the project's style guidelines and introduce no new warnings.
• The changes are fully tested and pass the CI checks.
• I have reviewed my own code changes.

If PR contains AI-assisted content:

• I have disclosed the use of AI tools in the PR description as per our AI Usage Guidelines.
• AI-assisted commits include an Assisted-by: [Model Name] via [Tool Name] footer.
• I confirm that I have personally reviewed and understood all AI-generated content, and accept full responsibility for it.

[github-actions]

PR Preview Action v1.8.1
🚀 View preview at https://Munich-Quantum-Software-Stack.github.io/QDMI/pr-preview/pr-511/
Built to branch gh-pages at 2026-08-24 12:51 UTC. Preview will be ready when the GitHub Pages deployment is complete.

[codecov]

Codecov Report

❌ Patch coverage is 91.39785% with 8 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
examples/driver/qdmi_example_driver.cpp	91.3%	8 Missing ⚠️

@@                    Coverage Diff                     @@
##           codex/multi-program-jobs    #511     +/-   ##
==========================================================
+ Coverage                      90.9%   91.4%   +0.5%     
==========================================================
  Files                             7       7             
  Lines                           861     891     +30     
  Branches                        181     192     +11     
==========================================================
+ Hits                            783     815     +32     
+ Misses                           78      76      -2     

Flag	Coverage Δ
cpp	91.4% <91.3%> (+0.5%)	⬆️

Files with missing lines	Coverage Δ
include/qdmi/constants.h	100.0% <ø> (ø)
examples/driver/qdmi_example_driver.cpp	95.1% <91.3%> (+1.6%)	⬆️

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[burgholzer]

This is mostly looking good already. There's a few minor things that I would like to fix.

[burgholzer]

Okay, this should be good now.