Add iteration controls, GIF export, runtime metrics, and custom colormap to waveform inversion script

[Fuwsusu]

Motivation

• Provide controllable iteration flow and the option to stop early to speed up debugging and interactive runs by adding requestedIterations and runAllIterations logic.
• Improve observability of inversion progress by computing and logging per-iteration timing and quantitative metrics (data misfit and time-shift residuals).
• Produce per-iteration visual output (animated GIF) and improve visual contrast with a soft red-blue colormap for easier interpretation of velocity/attenuation updates.

Description

• Added iteration, GIF and display controls including runAllIterations, requestedIterations, saveGIF, gif_delay, and gif_save_every, plus a soft red-blue colormap cmap_rb used for image displays.
• Implemented early-stop logic in the main inversion loop so the run stops when iter exceeds requestedIterations unless runAllIterations is true.
• Introduced per-iteration metrics and timing variables ITER_TIME_SEC, PHI_ITER, DELTA_PHI_ITER, TAU_SHIFT_ITER, and prev_phi_k, and accumulated phi_k and tau_k inside the adjoint build; metrics are displayed each iteration.
• Added animated GIF export (gif_filepath) that appends frames per iteration when saveGIF is enabled, updated final save to include the new arrays, and printed main loop and total script runtime.
• Switched plot colormaps from gray to the new cmap_rb and updated the results save path to include the new metrics.

Testing

• No automated tests were executed for this change.

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Codex Task