Migrate JAXopt and research-test deprecation boundaries

[ReidSurmeier]

This was generated by AI during triage.

Agent Brief

Category: enhancement
Summary: Remove the current solver and research-test deprecation warnings without changing accepted print-planning behavior.

Current behavior:
The maintained suites pass, but JAXopt reports that it is no longer maintained, the morphology repair uses the deprecated min_size form of the small-object filter, one research test returns a value, and the slow marker is not registered at the repository root.

Desired behavior:
The portable and research test commands should complete without these warnings. Solver migration must preserve measured optimization behavior; morphology migration must preserve the strict old threshold semantics; test-only warnings should be corrected without weakening assertions.

Key interfaces:

• The continuous optimization adapter used by the hybrid solver.
• The carved-region morphology repair contract around minimum component area.
• The repository-wide pytest marker and return-value contracts.

Acceptance criteria:

• A failing warning-as-error test captures each warning before implementation.
• The optimization adapter no longer depends on an unmaintained JAXopt API, with equivalent convergence tests.
• Morphology repair preserves the prior strict component-size boundary under the supported scikit-image version.
• Research tests return None and the slow marker is registered.
• The complete v23 and focused research suites remain green.

Out of scope:

• Changing the V1 Methodology gate.
• Tuning solver quality or accepting iter 13.
• Upgrading the dormant inherited frontend.