Agent writes via skill_manage (create/edit/patch/write_file) are now
constrained to prevent unbounded growth:
- SKILL.md and supporting files: 100,000 character limit
- Supporting files: additional 1 MiB byte limit
- Patches on oversized hand-placed skills that reduce the size are
allowed (shrink path), but patches that grow beyond the limit are
rejected
Hand-placed skills and hub-installed skills have NO hard limit —
they load and function normally regardless of size. Hub installs
get a warning in the log if SKILL.md exceeds 100k chars.
This mirrors the memory system's char_limit pattern. Without this,
the agent auto-grows skills indefinitely through iterative patches
(hermes-agent-dev reached 197k chars / 72k tokens — 40x larger than
the largest skill in the entire skills.sh ecosystem).
Constants: MAX_SKILL_CONTENT_CHARS (100k), MAX_SKILL_FILE_BYTES (1MiB)
Tests: 14 new tests covering all write paths and edge cases
