[clinic · EX-08] Implement a new chunking strategy

[akash-coded]

Exercise clinic. One long-running thread per exercise. Ask here rather than opening a
new thread — the answers accumulate where the next person will look for them.

Exercise: EX-08 — Implement a new chunking strategy · difficulty 🔴

What this exercise asks

Read the exercise first; this thread is for when you are stuck, not instead of it.

Three ways people get stuck on this one

1. Not producing stable chunk ids, which quietly breaks the incremental path — see ADR-0004.

2. Dropping the heading path, which is what makes a retrieved chunk attributable and is why contextual chunking did not help here (#37).

3. Registering the strategy but not adding it to the bake-off, so nothing ever measures it.

How to ask here

Post the numbers you got, the config that produced them, and what you already tried.
A question with a measurement in it gets answered in one round trip; a question without one
takes three.

If you have finished it, post the write-up in Show and Tell with the
[solution · EX-08] prefix rather than here — this thread stays for people who are stuck.