config + docs/PHASE7: example block + status -> Implement (Phase 7 commit #6)

R9-resolved single-owner of the status bump (commit #5 didn't touch
PHASE7.md). N5: PHASE0 §11 amendment landed in commit 3bad07b
(formulate); not re-applied here.

config.lua:
  - Commented-out `cost = { warn_at_dollars, warn_at_tokens }` block
    with parity to the Phase 1-6 example blocks.
  - Notes warn flags are independent (R4) and per-turn usage flows
    to session/*.jsonl for after-the-fact analysis.

docs/PHASE7.md:
  - Status header bumped: "Plan + review fold-in" -> "Implement"
  - Lists the 6 implement commits inline for traceability:
      7364963  broker: usage capture + opts widening
      7b4a9be  context: accumulator helpers
      8adebd5  repl: _record_usage + opts.category at 5 sites
      b30212a  safety + repl: opts.category for Norris + probe
      0d6ff93  repl: :cost meta surface
      this     config example + status bump

Phase 7 implementation is complete. Next inner-loop step is verify
(7) — user-driven smoke tests, then memory-update (8).

Regression: test_safety 87/87, test_router_model 31/31, repl loads.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

config.lua

@@ -264,4 +264,24 @@ return {
     -- Requires the external `tree-sitter` CLI plus configured parser-
     -- directories with cloned + built `tree-sitter-<lang>` grammars
     -- (see `:highlight on` for the install hints).
+
+    -- Phase 7 (docs/PHASE7.md): cost / usage observability. broker.lua
+    -- captures `usage` (+ `cost` for cloud) from every chat/chat_stream
+    -- call and routes via ctx:add_usage to a per-session accumulator.
+    -- `:cost` / `:cost detail` / `:cost reset` surface the totals.
+    -- The `cost` block below configures OPTIONAL warn thresholds —
+    -- a single status line fires the first time the cumulative
+    -- crosses each threshold. Default off. Useful when paid cloud
+    -- presets are in play so runaway-cost sessions get a nudge.
+    --
+    -- cost = {
+    --     warn_at_dollars = 0.50,    -- one-shot warn when cumulative cost crosses
+    --     warn_at_tokens  = 100000,  -- one-shot warn when cumulative tokens crosses
+    -- },
+    --
+    -- Both flags are independent (R4 — first-to-fire doesn't suppress
+    -- the other); `:cost reset` re-arms both. Per-turn usage is also
+    -- written to session/*.jsonl (assistant-turn `usage` field) for
+    -- after-the-fact scripting; cross-session aggregation deferred
+    -- to a future phase (Q-C2).
 }

docs/PHASE7.md

@@ -2,7 +2,7 @@
 
 **Project:** aish — AI-augmented conversational shell
 **Document:** Phase 7 Requirements, Architecture & Design Decisions
-**Status:** Plan + review fold-in (tree at `0f14dc1`)
+**Status:** Implement (6 commits landed: 7364963, 7b4a9be, 8adebd5, b30212a, 0d6ff93, this)
 **Date:** 2026-05-16
 
 **Review findings (independent Sonnet agent, 2026-05-16) — 3 BLOCKERs