Refactor index.js generation to use Jinja2

[google-labs-jules]

Refactor index.js generation to use Jinja2 templating.

• Added jinja2 dependency.
• Created fitsmap/templates/index.js.j2.
• Updated fitsmap/cartographer.py to use the template.
• Removed legacy Javascript string building functions.
• Verified output matches existing test expectations (whitespace and structure).

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PR created automatically by Jules for task 3161396819139761381 started by @ryanhausen

[google-labs-jules]

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 95.15%. Comparing base (1dd195b) to head (7253418).
⚠️ Report is 1 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #108      +/-   ##
==========================================
- Coverage   95.33%   95.15%   -0.18%     
==========================================
  Files           6        6              
  Lines         814      785      -29     
==========================================
- Hits          776      747      -29     
  Misses         38       38              

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[Copilot]

Pull request overview

This PR refactors the index.js and index.html generation from string concatenation to Jinja2 templating. The refactoring aims to improve maintainability by separating template structure from Python logic.

Key Changes:

• Added Jinja2 as a dependency (version >=3.1.6)
• Created two new Jinja2 templates: index.js.j2 and index.html
• Refactored build_index_js() to use the template instead of string building
• Removed 7 legacy string-building functions that are no longer needed
• Updated test suite to remove tests for deleted functions

Reviewed changes

Copilot reviewed 6 out of 7 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
pyproject.toml	Added Jinja2 dependency (>=3.1.6)
uv.lock	Updated lock file with Jinja2 dependency
fitsmap/templates/index.js.j2	New Jinja2 template for generating index.js with map configuration
fitsmap/templates/index.html	New Jinja2 template for generating HTML page structure
fitsmap/cartographer.py	Refactored to use Jinja2 templates; removed legacy string-building functions
fitsmap/tests/test_cartographer.py	Removed tests for deleted functions; improved integration test file comparison
MANIFEST.in	Added index.html template to distribution (missing index.js.j2)

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[ryanhausen]

@jules

Undo the changes you made in the last commit

[google-labs-jules]

@jules

Undo the changes you made in the last commit

Undone the changes to fitsmap/cartographer.py as requested. Note that test_build_html might fail again due to this revert, as I was trying to fix a test failure there.