0.15.0 — deferred-exposure pass + config kill-switch removal

Deferred-exposure pass + config kill-switch removal (net −660 lines):

Deferred tools

• 56 cold tools across 19 modules register with exposure: "deferred" — pi declares only hot direct tools in the system prompt (fresh session: 23 tools ≈ 438 tokens, was ~79 ≈ 21K)
• tool_search loads them on demand; the bundle re-activates tool_search on session_start whenever a deferred tier exists
• Registry tools?: string[] → deferredTools?: string[] tier lists; ceulen.disabledTools + lib/tools.ts deleted outright

/config

• Module Enable rows, synthesized Enable-only sections, and per-tool toggle rows removed — ceulen.disabled remains the settings-only escape hatch (no UI)
• Built-in tools section is 9 rows (tool_search removed — ceulen owns its activation)

Usage report fix

• computeContextBreakdown counted ALL registered tool schemas as "System tools" — now counts active tools only (what the model actually receives) and discloses the deferred tier separately: Tools (N active · X tokens in prompt · M deferred not in prompt (Y))
• Fresh-session prompts were never carrying the 21K the old report showed

Housekeeping

• Prompt guidance updated for on-demand loading (serena guidance matches tool_search; munin protocol + rules rulebook point at tool_search first)
• Tests: 2765 pass / 0 fail (+1 deferred-tier disclosure suite); typecheck clean