D61 — Instructions: auto-generated agents section + curated instructions.md (WP5)

Context. D56 generates the instructions block with archives only + generic operational instructions. It says nothing about the agents provisioned by the same KB (D48/D55): the main agent does not know local subagents exist nor when to delegate. There is also no place where the operator can write domain-specific orchestration directives.

Decision. generateKBInstructions (signature and materialization mechanism unchanged) adds two optional trailing sections, each omitted if empty: (1) an auto-generated agents section (name + description from the frontmatter of agents/<nome>.md, sorted by name); (2) an optional curated file <kbRoot>/instructions.md, free text included verbatim. The hash remains sha256(generateKBInstructions(...)): no change to BuildManifest, drift is still detected because the function now also reads these files. instructions.md is not a concept: it lives outside data/, never indexed nor materialized as a standalone file. Discarded alternatives. instructions.md as an additional skill/agent (it would require a new kind and its own destination, instead of enriching the already injected block); keeping it outside the KB in server config (it would lose the git versioning shared with the rest of the KB). Details: docs/sync.md §Instructions.