[priyam0k]

Summary of Changes

Adds the tutorial notebook for Friedland Chapter 12 covering Exhibits I, II, and III, and registers it in _toc.yml. Exhibit III natively leverages \cl.ImpliedCaseDevelopment\ and \cl.Chainladder\ for Approach #2.

Related GitHub Issue(s)

#588

AI/LLM Usage

Used basic model for formatting markdown tables and cell text.

Additional Context for Reviewers

Tutorial notebook for Friedland Chapter 12 (Case Outstanding Development Technique). Rebased onto current \main\ with all 22 CI checks and ReadTheDocs build passing.

Submitter's Checklist

• I have reviewed and am adhering to the standards outlined in the project Governing Doc.
• The PR subject title summarizes the changes, with one proper prefix ([FIX], [FEAT], [DOCS], [TST], [CHORE], or [BRK]).
• I am a human (not a bot), and this PR form is written by a human.

[github-actions]

Pyright Type Completeness

View the full pyright --verifytypes output for this commit

Project (full chainladder package, at this PR's head): 15.9% of exported symbols fully typed (241 / 1520)

	Known	Ambiguous	Unknown	Total
Project (head)	241	106	1173	1520

Other symbols referenced but not exported by chainladder: 13

	Known	Ambiguous	Unknown	Total
Other (head)	3	1	9	13

Symbols without documentation:

• Functions without docstring: 340
• Functions without default param: 0
• Classes without docstring: 8

Patch (exported symbols added or changed by this PR): no exported symbol type-completeness changes detected.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 94.35%. Comparing base (67dea50) to head (a6eb37f).

Additional details and impacted files

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  Coverage   94.35%   94.35%           
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  Files          97       97           
  Lines        6183     6183           
  Branches      796      796           
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  Hits         5834     5834           
  Misses        225      225           
  Partials      124      124           

Flag	Coverage Δ
unittests	94.35% <ø> (ø)

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[henrydingliu]

@priyam0k thanks for picking up this chapter.

after the first couple of exhibits, there's not a lot of chainladder but mostly pandas. if the existing caseoutstanding estimator can't readily reproduce what friedland is doing, we should be enhancing our library.