Record token usage per turn and show daily, weekly and all-time totals by host

Deployment/master.conf.template

@@ -1644,6 +1644,23 @@
     AI_MEMORY_FILE="$DATA_DIR/ai_memory.md"
     AI_MEMORY_MAX_CHARS=4000        # ~1000 tokens — truncated with a notice if exceeded
 
+# ━━━ AI Token Accounting ━━━
+# One row per completed turn, appended by whichever path ran it — the WebGUI worker and the
+# ai_query.sh CLI both write here, so the totals are not silently the tab's alone. Format is
+# pipe-delimited to match the other data/*.db files:
+#
+#   date|time|host|profile|source|prompt_tokens|completion_tokens|tok_s
+#
+# The host column records where the turn ran, not where it is read. Each host keeps its own
+# data/ and nothing syncs it, so a host only ever sees its own rows — the column is there so
+# the file is already shaped right if the partner payload fetch is ever extended to carry it.
+# A column added later cannot be backfilled.
+#
+# Retention is by row count rather than age: pruning is considered only when the file passes a
+# size threshold, so an ordinary turn costs one stat() and an append.
+    AI_TOKEN_DB="$DATA_DIR/ai_token_history.db"
+    AI_TOKEN_RETAIN_ROWS=20000      # oldest rows dropped past this — years of ordinary use
+
 # ━━━ AI Feature Toggles ━━━
 # Tier 1 is narration — it cannot change a decision. Tier 2 adds context to a decision a script
 # already made. Tier 3 assists a human. Enable in that order, and give each one weeks.