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/core/index.md

@@ -13,6 +13,8 @@ These files define the structural conventions that govern the agent system itsel
 * [AGENTS.md Format Specification](agents-md-format.md) — Canonical structure and conventions for the system-level instruction file that governs agent behavior.
 * [Pi Settings System](settings.md) — pi-era `settings.json` record (archive): providers, models, packages, subagent overrides.
 * [dankvoice](dankvoice.md) — Cloned-voice vocalization extension: `/say` and auto-speak over frank-tts, endpoint read from `agent/models.yml`.
+* [OMP Status Line Customization](statusline.md) — How presets, composer shapes, and segment arrays actually interact; the fleet's tuned bar. (moved from /pi/, 2026-10-19)
+* [OMP Subagent Limits & Fan-out Policy](subagent-limits.md) — Live caps: concurrency 2, no nested spawns (the `maxRecursionDepth: 0` trap), per-endpoint in-flight ceilings, isolation policy. (moved from /pi/, 2026-10-19)
 
 ## Change Tracking