p2: digest with in-sift FIFO, SQLite caches, Honcho context, recover

Dixie is capped (max_inflight 2, queue_depth 8, queue_wait 20s) and
never queued on llama-server. Streaming chat, thinking off, 45s
fallback to clean. Digest and chunk-embedding caches are
content-addressed SQLite (Honcho context is not cached). Recover
uses the guarded Fetcher. guardian-star is refused in code.

vendor/modernc.org/sqlite/lib/sqlite_g_000000000001c014.go

@@ -0,0 +1,7 @@
+// Code generated by modernc.org/undup from the per-target sqlite_*.go files; DO NOT EDIT.
+
+//go:build (freebsd && 386) || (freebsd && arm) || (netbsd && amd64) || (openbsd && amd64) || (openbsd && arm64)
+
+package sqlite3
+
+type t__fd_mask = uint32