Feature/software icon export on pr11

[timoteuszelle]

This PR is stacked directly on top of PR #11 (Import and Export patterns by @MidnightJava) and adds a software-oriented JSON export feature. All of the behavior from PR #11 remains unchanged.

Relationship to PR #11

• This branch is based on the current head of PR Import and Export patterns #11.
• All of Mark’s changes (import/export, persist checkbox, wake loop, etc.) are included as-is.
• This PR only adds a separate JSON export path for software workflows.

That means maintainers can:

• Merge PR Import and Export patterns #11 alone, or
• Merge this PR instead, which includes PR Import and Export patterns #11 plus the software JSON export additions.

Additions in this PR

1. UI: “Export for Software” section

Below the existing Import/Export buttons, this PR adds:

• Format options

  • Binary (0/1)
  • Grayscale (0–255) (default)

• Layout

  • Fixed column-major layout (9 x 34), matching the physical LED matrix orientation and my icon library usage.

• Buttons

  • Export Left (JSON)
  • Export Right (JSON)

The existing Import/Export buttons and the 39‑byte hardware pattern format from PR #11 remain exactly as implemented there.

2. JSON export format

The new buttons generate a .json file with:

• Shape

  • 9 x 34 (outer array = columns, inner array = rows)

• Values

  • Binary mode: 0 (off) or 1 (on)
  • Grayscale mode: 0 (off) or 255 (fully lit)

This is derived from the existing convention where matrix[row][col] === 0 means “LED on”.

Filenames follow this pattern, e.g.:

• matrix_left_grayscale_colmajor.json
• matrix_right_binary_colmajor.json

3. Implementation details

• index.html

  • Adds the “Export for Software” section with:
    • A format radio group (binary vs grayscale).
    • Fixed-layout note (“fixed column-major (9x34)”).
    • Export Left/Right (JSON) buttons.

• app.js

  • Calls initSoftwareExportOptions() in the main $(function() { ... }).
  • Adds initSoftwareExportOptions():
    • Wires #exportLeftSoftwareBtn / #exportRightSoftwareBtn to the new behavior.
    • Reads the exportFormat radio value.
  • Adds exportMatrixSoftware(matrix, side, grayscale):
    • Builds a fixed column‑major 9 x 34 array from the existing matrix_*.
    • Maps internal 0/1 cells to 0/1 or 0/255.
    • Triggers a JSON download with a descriptive filename.

Compatibility

• No changes to the 39‑byte hardware import/export from PR Import and Export patterns #11.
• JSON export is fully additive and only affects the new “Export for Software” UI.
• Intended for use cases like the LED matrix monitoring project (icon libraries, grayscale icons, etc.).

Happy to adjust naming/text if you prefer different terminology for the new options.