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%)

org/symbolic-memory.org

@@ -82,7 +82,7 @@ Returns a plist: (:total <n> :by-type <alist> :by-todo <alist>
 ** Skill Registration
 
 #+begin_src lisp
-(defskill :passepartout-system-memory
+(defskill :passepartout-symbolic-memory
   :priority 100
   :trigger (lambda (ctx) (eq (getf (getf ctx :payload) :sensor) :introspection))
   :deterministic (lambda (action ctx)