Steps 266-268: Phase 10a — semantic annotation core + sidecar persistence (32/32 tests)

Step 266: 5 semantic annotation AST types (Intent, Complexity, Risk,
Contract, SemanticTag) with JSON roundtrip and compact AST integration.
Step 267: Sidecar AST persistence (.whetstone/<file>.ast.json) with
save/load/list RPC methods, MCP tools, and permission enforcement.
Step 268: Phase 10a integration tests — multi-file sidecar workflow,
all 5 types in compact view, idempotent roundtrip, source isolation.

Also includes Sprint 10 plan, GUI/installer polish, and Emacs integration fixes.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

editor/src/CodeEditorRenderVisible.h

@@ -144,8 +144,7 @@
                     }
                     if (hoverSuggestion) {
                         std::string tip = suggestion.label + " (" +
-                            std::to_string(suggestion.confidence) + ")
-" +
+                            std::to_string(suggestion.confidence) + ")\n" +
                             suggestion.reason;
                         renderRichTooltip("suggestion_marker_" + std::to_string(ln),
                                           tip,
@@ -314,8 +313,7 @@
                         else if (c == '	') c = '>';
                     }
                 }
-                if (!chunk.empty() && chunk[chunk.size() - 1] == '
-') {
+                if (!chunk.empty() && chunk[chunk.size() - 1] == '\n') {
                     chunk.pop_back();
                 }