feat: add interactive Plotly circuit diagram visualization

[kawacukennedy]

Summary

Implements PlotlyCircuitDiagram — an interactive circuit diagram renderer that returns a plotly.graph_objects.Figure via the existing circuit.show() interface. Resolves #1250.

Changes

• New file: src/braket/circuits/graphical_diagram_builders/plotly_circuit_diagram.py — Full Plotly rendering: gate boxes, control/anti-control dots, SWAP markers, connections, barriers, result types, qubit labels, moment labels, footer metadata
• New file: test/unit_tests/braket/circuits/test_plotly_circuit_diagram.py — 68 tests covering layout, tooltips, verbatim detection, column geometry, and figure output
• New file: examples/plotly_circuit_visualization.py — Usage examples including parameterized circuits, verbatim boxes, result types, and HTML export
• Modified: src/braket/circuits/circuit.py — show() accepts "interactive" argument, imports PlotlyCircuitDiagram on demand
• Modified: src/braket/circuits/graphical_diagram_builders/__init__.py — Export PlotlyCircuitDiagram
• Modified: pyproject.toml — Added interactive = ["plotly"] optional dependency group

Key Features

• Hover tooltips on every gate showing name, target qubits, and parameters
• Collapsible verbatim boxes via Plotly updatemenus toggle (collapsed by default)
• Pure Plotly — no Dash, no callbacks, works in Jupyter and standalone scripts
• Optional dependency — pip install amazon-braket-sdk[interactive]
• No regressions — all 76 existing Matplotlib tests pass unchanged

Testing

# Plotly tests (68)
python -m pytest test/unit_tests/braket/circuits/test_plotly_circuit_diagram.py -v

# Matplotlib tests (76, no regressions)
python -m pytest test/unit_tests/braket/circuits/test_matplotlib_circuit_diagram.py -v

# Lint
pycodestyle --max-line-length=79 src/braket/circuits/graphical_diagram_builders/plotly_circuit_diagram.py
pycodestyle --max-line-length=79 test/unit_tests/braket/circuits/test_plotly_circuit_diagram.py

Disclosure

This contribution includes code co-authored with an AI assistant (big-pickle).

[kawacukennedy]

👋 Hi team — this PR adds interactive Plotly-based circuit diagram visualization to the SDK (resolves #1250).

Key highlights:

• 68 unit tests covering layout, tooltips, verbatim detection, column geometry, and figure output
• Hover tooltips on every gate showing name, target qubits, and parameters
• Collapsible verbatim boxes via Plotly updatemenus (collapsed by default)
• Pure Plotly — no Dash, no callbacks, works in both Jupyter and standalone scripts
• Optional dependency — pip install amazon-braket-sdk[interactive]
• No regressions — all 76 existing Matplotlib tests pass unchanged
• Example script in examples/plotly_circuit_visualization.py

Would love a review when someone has a chance! @speller26 @krneta