docs(pi): unify split package trees; move live OMP pages to core

Two directories documented one concept (pi npm packages): top-level
packages/ (browser-use, permission-system) and pi/packages/ (peon,
web-access, subagents). Merged into pi/packages/ — one row per package
in a single index, detail pages kept as archive records. The root
index's 'OMP packages and skills' section was doubly wrong (packages/
was pi, not OMP); it becomes a Skills tooling section pointing at the
consolidated /skills/ tree.

Moved the two LIVE omp pages out of the retired-harness banner:
pi/statusline.md -> core/statusline.md, pi/subagent-limits.md ->
core/subagent-limits.md (both document omp behavior against
agent/config.yml + the installed bundle; pi/index.md itself admitted
the mis-shelf). Retargeted every inbound link (core/index, system/
dankserver, log x2, pi/index, settings x2, moved files' own xrefs).

Refs #29

omp-docs/pi/packages/pi-peon.md

@@ -81,5 +81,5 @@ The `/peon` command opens an interactive settings modal with:
 
 ## See Also
 
-- [packages](../../packages/index.md) — Package overview
+- [Pi Packages](index.md) — Package overview
 - [pi](../index.md) — Pi configuration