Create visualizations for presentations

Create a set of static figures illustrating nested-pandas' data model and scientific usage patterns. These should be added to the [project's presentation deck ](https://docs.google.com/presentation/d/1Z5B6A69BUBUc4vRz1qncC4ygaj98aMJiRiQFgvzh8tI/) to be used for the presentation to the broad astronomical community.

The goal is to have figures that convey what nested-pandas does and why it matters, so that astronomers familiar with large-scale data analysis can quickly grasp the value and consider adopting it in their workflows.

### Suggested figures (some of these already avaliable at various locations):

#### Data Model Figures
- [ ] **Nested structure diagram** — visual comparison of flat vs. nested
DataFrame layout (e.g., per-object metadata + per-observation time
series in a single structure)
- [ ] **Schema diagram** — how a NestedFrame maps to a nested column,
showing dtypes and nesting levels

#### Usage / Workflow Figures
- [ ] **End-to-end workflow** — schematic of ingesting catalog with time-series
data, querying, and extracting results using nested-pandas API
- [ ] **Code + output side-by-side** — a short representative code snippet
alongside its resulting NestedFrame output (table or diagram)

#### Performance / Scale Figure
- [ ] **Performance comparison** — benchmark plot comparing nested-pandas
to a naive flat-table approach on a realistic astronomical dataset
(e.g., object catalog with light curves)

### Acceptance Criteria
- [ ] Each figure is self-contained and readable at conference-slide scale
(no microscopic labels)
- [ ] Figures use consistent styling (color palette, fonts) suitable for
a light-background slide deck
- [ ] Exported as high-resolution PNG or SVG
- [ ] Figures added to the shared [Google Slides deck](https://docs.google.com/presentation/d/1Z5B6A69BUBUc4vRz1qncC4ygaj98aMJiRiQFgvzh8tI/)

Review the linked Google Slides deck, the nested-pandas API, and the suggested existing figure locations before planning the set of visuals. Done means the figures explain the data model and usage patterns, remain readable and consistently styled at slide scale, are exported as PNG or SVG, and are added to the shared deck.

Written by the indexing model from the issue text.