content: Phase 5 — rich inline text via structured runs (861/861)

CtText.text may be a list of runs (text marks href); CtHeading/CtQuote rich,
CtCode verbatim. New runs.sx overrides render/markdown/text methods (byte-
identical for plain strings, opt-in). 4 modes: HTML tags / markdown / nested
SX / plain asText (drift-proof). find-replace per-run marks-preserving;
search across run boundaries; CRDT block-granularity LWW; data+wire round-trip.
Runs are a Smalltalk-renderable list (not a dict — substrate can't read dict
fields under nested render dispatch). +36 tests (44 suites). Phase 6 (char-
level inline CRDT) recorded as future.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

lib/content/scoreboard.json

@@ -8,6 +8,7 @@
     "page": {"pass": 7, "fail": 0},
     "page-full": {"pass": 4, "fail": 0},
     "markdown": {"pass": 20, "fail": 0},
+    "runs": {"pass": 36, "fail": 0},
     "text": {"pass": 20, "fail": 0},
     "section": {"pass": 25, "fail": 0},
     "compose": {"pass": 17, "fail": 0},
@@ -44,7 +45,7 @@
     "md-doc": {"pass": 12, "fail": 0},
     "fed": {"pass": 20, "fail": 0}
   },
-  "total_pass": 825,
+  "total_pass": 861,
   "total_fail": 0,
-  "total": 825
+  "total": 861
 }