MEP-45 research notes

These twelve notes are the deep research that fed MEP 45. Mochi-to-C transpiler. They are informative; the MEP body is normative. Each note is self-contained and can be read independently. Cross-references use [[note-slug]] markers.

#	Title	Topic
01	Language surface	Mochi language features the C target must lower
02	Design philosophy	Why C, why monomorphisation, why differential testing
03	Prior-art transpilers	Nim, Crystal, Vala, OCaml, Roc, Koka, Lean 4, etc.
04	Runtime building blocks	GC, allocator, coroutines, channels, strings, JSON, HTTP, time
05	Codegen design	aotir IR, name mangling, decision trees, setjmp/longjmp
06	Type-system lowering	Type-by-type mapping to C
07	C target and portability	Tier-1/2/3 triples, zig cc, ABI
08	Dataset pipeline lowering	Query DSL, joins, group_by, datalog
09	Streams and agents	M:N scheduler, fibers, channels
10	Build system	mochi build pipeline, cache layout
11	Testing and CI gates	Differential testing vs vm3, sanitiser matrix
12	Risks and alternatives	Risk register, alternatives rejected

See MEP 45 for the normative specification and implementation tracking for per-phase progress.