Correct and validate the ballet examples (demi-plié, elevé/relevé, pirouette, chassé)

[a-baran-orhan]

Focused split of Workstream 4 from the dance UAT umbrella #91.

Treat the current ballet examples as experimental until reviewed by someone with relevant dance knowledge. Update source examples, generated pages, thumbnails/GIFs, prompt examples, and regression tests together. Confirm terminology and movement with a dance-domain reviewer before marking any example ready.

Demi-plié

• Preserve first-position turnout throughout descent and recovery.
• Keep both soles fully planted (no heel lift / lateral skating).
• Verify knees track over the turned-out feet.
• Revisit the dorsiflexion requirement under the selected ballet/contact profile (see ROM profiles and ground-contact invariants for domain-aware ranges #102).

Elevé and Relevé

• Rename the current rise-without-plié example from "Relevé" to "Elevé".
• Start the Elevé example from first-position, not generic standing.
• Preserve turnout during rise and controlled lowering.
• Add a distinct Relevé example that begins with a demi-plié before rising.

Pirouette

• Start in first position; preserve hip external rotation throughout.
• Turn toward the right gesture leg; third-position arm shape into the turn, arms at a consistent height.
• Revisit plantarflexion under the ballet profile.
• Represent spotting; decide whether it needs a dedicated gaze/focus/spot construct.
• Validate support-foot contact, turn direction, gesture-leg path, landing, and loop reset with automated invariants.

Chassé

• Compare against an appropriate reference selected with a reviewer.
• Correct step-close-step mechanics, weight transfer, foot contact, turnout, timing, and travel path.
• Verify root translation + foot constraints don't make the feet slide while cues claim stepping.
• Record the reference and validation notes in the example.

Acceptance

• Every published dance example has named reference material and review status.
• Cues describe only encoded, visibly rendered motion.
• Key contacts, paths, joint ranges, turn direction, and final orientation have deterministic tests.
• Updated public captures generated only after movement tests pass.

Priority: P0 for naming/status + demi-plié heel-lift diagnosis; P1 for full pirouette/chassé correction.

Current statuses: pirouette is experimental; demi-plie, releve, tendu, chasse are currently ready and should be reviewed before staying so.