Some random (hopefully additive and helpful) thoughts:

Many companies have older code bases / databases that can be somewhat well defined (and somewhat not). If things have been slowly iterating over 35 years, there's a lot of undocumented edge behavior that may occur; it may be beneficial to have a step before Edge Case Catalog where there's some kind of prompting to catalogue how the inputs and outputs work, and then find the different inputs and outputs - and then confirm that with Input A and Output A that it works as expected. (Legacy systems often have weird orchestration that nobody remembers.)

(Sub-note: This is somewhat part of the provable properties catalog; while this step could be placed there, it would require a re-run of edge case catalog build potentially, which isn't a bad thing.)

A small note that I personally think is a good idea is better code commenting than has been outlined here - the spec itself should be woven into the code with potentially slightly over-commenting for each aspect, code spec gets lost. The code itself should serve as context, especially in the TDD stage.

I think it's implicit but may be worth overtly stating that for the Code Quality check in Phase 3 that it also checks on a zero-trust basis, and doesn't include things like hardcoded keys.

I'm not sure what Chainlink is (sorry!) but I like the ideas outlined around the decomposition - but it misses stringing everything together end-to-end in the way outlined here (it asks to create each part, but never actually weaves the whole together).

Something not covered - is sequencing work and decomposition of work. A spec can create multiple dependencies within itself, requiring things to be worked on in a specific order.