HS-plan: log cluster 29 blocked

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

plans/hs-conformance-to-100.md

@@ -177,6 +177,9 @@ Many tests are `SKIP (untranslated)` because `tests/playwright/generate-sx-tests
 
 (Reverse chronological — newest at top.)
 
+### 2026-04-24 — cluster 29 hyperscript:before:init / :after:init / :parse-error (blocked)
+- **2b486976** — `HS-plan: mark cluster 29 blocked`. sx-tree MCP file ops returning `Yojson__Safe.Util.Type_error("Expected string, got null")` on every file-based call (sx_read_subtree, sx_find_all, sx_replace_by_pattern, sx_summarise, sx_pretty_print, sx_write_file). Only in-memory ops work (sx_eval, sx_build, sx_env). Without sx-tree I can't edit integration.sx to add before:init/after:init dispatch on hs-activate!. Investigated the 6 tests: 2 bootstrap (before/after init) need dispatchEvent wrapping activate; 4 parser tests require stricter parser error-rejection — `add - to` currently parses silently to `(set! nil (hs-add-to! (- 0 nil) nil))`, `on click blargh end on mouseenter also_bad` parses silently to `(do (hs-on me "click" (fn (event) blargh)) (hs-on me "mouseenter" (fn (event) also_bad)))`. Fundamental parser refactor is out of single-cluster budget regardless of sx-tree availability.
+
 ### 2026-04-24 — cluster 19 pick regex + indices
 - **4be90bf2** — `HS: pick regex + indices (+13 tests)`. Parser: `pick items/item EXPR to EXPR` accepts `start`/`end` keywords; `pick match`/`pick matches` accept `| <flag>` after regex; `pick item N` without `to` still works. Runtime: `hs-pick-items`/`hs-pick-first`/`hs-pick-last` polymorphic for strings (slice) in addition to lists; `hs-pick-items` resolves `start`/`end` sentinel strings and negative indices at runtime; new `hs-pick-matches` wrapping `regex-find-all`; `hs-pick-regex-pattern` accepts `(list pat flags)` shape with `i` flag. Suite hs-upstream-pick: 11/24 → 24/24. Smoke 0-195 unchanged.