Theory: volatile automata and their optimizations

Paper-grounded theory for the in-memory dictionary structures that the docs/theory/scdawg/ suffix-automaton series does not already cover: DAWG minimization, the double-array trie, and the two optimizations the mutable backends lean on (Bloom pre-filtering and bit-parallel child scanning). It is the theoretical companion to the implementation guides and the in-memory architecture. Notation follows docs/notation.md.

Where each structure's theory lives

The theory corpus is split by structure. This cluster fills the gaps for the volatile family:

Structure	Theory
Suffix automaton / CDAWG / SCDAWG	theory/scdawg/ (its own 7-part series)
Adaptive Radix Tree (persistent)	theory/disk-tries/
DAWG minimization (Daciuk MADFA + signature hashing)	01-dawg-minimization.md
Double-array trie (Aoe / Yata BASE·CHECK)	02-double-array-tries.md
Bloom filters (probabilistic membership)	03-bloom-filters.md
Bit-parallel child scan (PathMap's ByteMask)	04-bit-parallel-child-scan.md

Reading order

1. 01-dawg-minimization.md — why a trie collapses into a DAWG and how the crate minimizes incrementally with a single u64 signature per node.
2. 02-double-array-tries.md — how a trie becomes two integer arrays with arithmetic, pointer-free transitions.
3. 03-bloom-filters.md — the probabilistic membership filter, its false-positive arithmetic, and an honest account of its (limited) role on the current read path.
4. 04-bit-parallel-child-scan.md — how child sets are scanned with word-parallel bit tricks, and where (and where not) SIMD appears in this crate.

A note on honesty

Two of these docs correct a common over-claim. The Bloom filter and any "SIMD child scan" are often described as if they were on every hot path; in libdictenstein they are not. The DAWG read path is an exact wait-free traversal that consults no Bloom filter (the with_config capacity argument is vestigial), and the volatile tree contains no SIMD at all — the only SIMD in the crate is the persistent ART Node16 byte scan. These docs state the theory and where the code actually uses it.