feat: conversion-driven extensions — resolvers, DefineTool, hooks, ops controls

Phase 9a (ADR-0014): Registry.RegisterResolver for dynamic tiers;
DefineTool[Args] typed tools; Usage cache/reasoning detail fields wired
through anthropic/openai/google; WithPromptCaching (Anthropic
cache_control); agent supervision hooks (WithMaxStepsFunc, WithSteer,
WithCompactor, WithToolErrorLimits + ErrToolLoop); health
Bench/Unbench/Snapshot; ChainConfig.Observer failover events.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

progress.md

@@ -1,5 +1,19 @@
 # progress
 
+## 2026-06-10 — Phase 9a: conversion-driven library extensions
+
+**Landed (ADR-0014):** RegisterResolver (dynamic DB-backed tiers, static
+aliases win, recursive + cycle-guarded), DefineTool[Args] (typed tools
+over SchemaFor), Usage cache/reasoning detail fields populated by
+anthropic/openai/google, WithPromptCaching (Anthropic top-level
+cache_control), agent hooks (WithMaxStepsFunc, WithSteer, WithCompactor —
+non-fatal on error, canonical transcript stays uncompacted —
+WithToolErrorLimits with ErrToolLoop), health Bench/Unbench/Snapshot,
+ChainConfig.Observer failover events (attempt/bench/skip). Full hermetic
+coverage for each.
+
+**Next:** Phase 9b — the mort conversion branch.
+
 ## 2026-06-10 — Phase 8: live validation against real Ollama Cloud
 
 **All six checks PASS** (examples/live harness, OLLAMA_API_KEY from .env):