fix(planner): make placed thumbnails direct unplan controls

[PierreCsn]

Summary

• make a planned recipe thumbnail itself the click/tap/keyboard control that returns it to À placer;
• remove the permanent planned-card removal/order chrome while preserving Ma sélection authority;
• keep native drag available on desktop, suppress it for coarse-pointer mobile, and preserve direct slot placement;
• update the Planner contracts for the direct interaction model.

Relates to CookiGram/cookigram-core#252

Validation

• consumer python -m unittest discover -s tests -v (28 passed)
• consumer node --test tests/calendar-export.test.mjs (3 passed)
• Core builder with --content-dir consumer (pass)
• Core targeted pytest (37 passed)
• headless smoke at desktop and 390x844 (selection, slot click, placed-card click, drag move, no mobile native DnD, no horizontal overflow)