v0.8.2: cleanup + prose + structure + decomposition + budget + errors

Phase 1 — dedup + hardening (~9 items):
- Remove duplicate *skill-registry* defvar from core-skills
- Merge *backend-registry* into *probabilistic-backends*, delete backend-register
- Remove inject-stimulus alias, standardize on stimulus-inject
- Add pre-eval sandbox (skill-source-scan) blocks restricted symbols before eval
- Remove dead plist-get function; remove duplicate json-alist-to-plist export
- Fix read-framed-message whitespace DoS (4096-iteration max)
- Add *read-eval* nil to dispatcher-approvals-process read-from-string (RCE)
- Add test-op to ASDF; update .asd version 0.4.3→0.7.2

Phase 2 — prose + contracts + reorder:
- Split ROADMAP: 2623→1089 lines (TODO only), CHANGELOG: 260→1528 lines (full DONE history, 14 versions reverse chron)
- Add Contracts + Overview to 6 channel files + embedding-native + programming-standards + symbolic-scope
- Reorder 28 .org files: Contract → Test Suite → Implementation (TDD order)
- Add 7-phase inline prose to think() in core-reason
- Expand USER_MANUAL: 183→461 lines (10 new sections)

Phase 3 — decomposition + export organization:
- Decompose think() into think-assemble-prompt, think-call-llm, think-parse-response orchestrator
- Organize 188 exports into 16 grouped sections by module

Phase 4 — budget enforcement + error protocol:
- Per-session budget enforcement (SESSION_BUDGET_USD env var, budget-exhausted-p, guard in think-call-llm)
- Error condition hierarchy (6 conditions: pipeline-error, llm-error, gate-error, budget-error, protocol-error)
- Restarts in loop-process: skip-signal, use-fallback, abort-pipeline

org/security-policy.org

@@ -24,38 +24,6 @@ The Policy skill is intentionally simple. It has one job: ensure every action ha
 - Does NOT validate explanation quality — only length and presence.
 - Does NOT consider ~context~ — implementation ignores it currently.
 
-* Implementation
-
-** Package Context
-#+begin_src lisp
-(in-package :passepartout)
-#+end_src
-
-** Policy Logic (policy-compliance-check)
-;; REPL-VERIFIED: 2026-05-03T13:00:00
-#+begin_src lisp
-(defun policy-compliance-check (action context)
-  "Enforces constitutional invariants on proposed actions."
-  (declare (ignore context))
-  (let* ((payload (proto-get action :payload))
-         (explanation (proto-get payload :explanation)))
-    (if (and explanation (stringp explanation) (> (length explanation) 10))
-        action
-        (progn
-          (log-message "POLICY VIOLATION: Action lacks sufficient explanation.")
-          (list :type :LOG
-                :payload (list :level :warn
-                              :text "Action blocked: Missing or insufficient :explanation. Please justify your reasoning."))))))
-#+end_src
-
-** Skill Registration
-#+begin_src lisp
-(defskill :passepartout-security-policy
-  :priority 500
-  :trigger (lambda (ctx) (declare (ignore ctx)) t)
-  :deterministic #'policy-compliance-check)
-#+end_src
-
 * Test Suite
 
 #+begin_src lisp
@@ -90,3 +58,36 @@ The Policy skill is intentionally simple. It has one job: ensure every action ha
          (result (policy-compliance-check action nil)))
     (is (eq :LOG (getf result :type)))))
 #+end_src
+
+* Implementation
+
+** Package Context
+#+begin_src lisp
+(in-package :passepartout)
+#+end_src
+
+** Policy Logic (policy-compliance-check)
+;; REPL-VERIFIED: 2026-05-03T13:00:00
+#+begin_src lisp
+(defun policy-compliance-check (action context)
+  "Enforces constitutional invariants on proposed actions."
+  (declare (ignore context))
+  (let* ((payload (proto-get action :payload))
+         (explanation (proto-get payload :explanation)))
+    (if (and explanation (stringp explanation) (> (length explanation) 10))
+        action
+        (progn
+          (log-message "POLICY VIOLATION: Action lacks sufficient explanation.")
+          (list :type :LOG
+                :payload (list :level :warn
+                              :text "Action blocked: Missing or insufficient :explanation. Please justify your reasoning."))))))
+#+end_src
+
+** Skill Registration
+#+begin_src lisp
+(defskill :passepartout-security-policy
+  :priority 500
+  :trigger (lambda (ctx) (declare (ignore ctx)) t)
+  :deterministic #'policy-compliance-check)
+#+end_src
+