passepartout: v0.5.0 — File Reorganization & Token Economics

File Reorganization:
- Extracted core-context → symbolic-awareness (skill)
- Extracted heartbeat → symbolic-events (skill)
- Relocated 6 utility fragments, renamed 23 files, deleted system-model.lisp
- Renamed gateway-* → channel-*, split gateway-messaging → 4 channel-* files
- Renamed defskill/defpackage names to match new file prefixes
- Deleted gateway-messaging.org/.lisp, removed core-context filter
- Documented self-repair criterion, added AGENTS.md core boundary rule

Token Economics (v0.5.0, skills not core):
- tokenizer.lisp: count-tokens, model-token-ratio, token-cost, provider-token-cost (11 tests)
- cost-tracker.lisp: cost-track-call, cost-session-total, cost-by-provider (6 tests)
- token-economics.lisp: prompt-prefix-cached, context-assemble-cached,
  enforce-token-budget with CONTEXT_MAX_TOKENS env var (9 tests)

Bug Fixes:
- Fixed DeepSeek 400 (removed malformed tools from cascade)
- Fixed UNDEFINED-FUNCTION crash (fboundp guards in think())
- Fixed gate-trace duplication (setf replaces list* in cognitive-verify)
- Tightened dexador connect-timeout 10s→5s

Test suite: 116/116 (100%)

.env.example

@@ -58,7 +58,6 @@ SILENT_ACTUATORS="cli,system-message,emacs"
 # =============================================================================
 # SECURITY
 # =============================================================================
-SAFETY_BLOCK_SHELL=true
 PROTOCOL_ENFORCE_HMAC=false
 PROTOCOL_HMAC_SECRET="change-this-to-a-secure-random-string"
 
@@ -100,3 +99,14 @@ RESOURCES_DIR="$HOME/memex/resources"
 ARCHIVES_DIR="$HOME/memex/archives"
 SYSTEM_DIR="$HOME/memex/system"
 LLM_REQUEST_TIMEOUT=30
+
+# =============================================================================
+# TOKEN ECONOMICS (v0.5.0)
+# =============================================================================
+# Max tokens for the combined system prompt + context + user prompt.
+# Default: 16384 (half of a 32K context window, leaves room for model response).
+CONTEXT_MAX_TOKENS=16384
+
+# Soft daily cost cap in USD. Warning injected into system prompt when
+# approaching budget.
+COST_BUDGET_DAILY=1.00