fix(patches): validator portability, clearer docs, broader hook trigger

.superpowers/handoff/task-B2-report.md

@@ -0,0 +1,84 @@
+# Task B2 Report: Registry Validator Script
+
+## Status
+DONE — commit `e3e219e`: feat(patches): add registry validator script
+
+## File created
+`local/validate-patches.R` — written verbatim from the brief.
+
+## Step 2: Success case
+```
+$ Rscript local/validate-patches.R; echo "exit=$?"
+Patch registry OK (1 entrie(s)).
+exit=0
+```
+Matches expected output exactly.
+
+## Step 3: Failure case
+```
+$ cp local/patches/registry.json /tmp/reg.bak
+$ Rscript -e 'writeLines("[{\"package\":\"X\"}]", "local/patches/registry.json")'
+$ Rscript local/validate-patches.R; echo "exit=$?"
+Error in vapply(reg, function(e) { : values must be length 1,
+ but FUN(X[[1]]) result is length 0
+Execution halted
+exit=1
+$ cp /tmp/reg.bak local/patches/registry.json
+```
+
+Exit code is 1 as required.
+Note: the broken entry (missing `versions`) causes the `vapply` call to crash with an R runtime error before reaching the `validation FAILED` print path.
+The error message is different from the brief's expected text, but the exit code contract (exit=1) is met.
+This is a behaviour of the verbatim script from the brief — not a deviation.
+
+## Registry restore verification
+After `cp /tmp/reg.bak local/patches/registry.json`, `git status` shows no diff on `local/patches/registry.json` — it is byte-identical to the original.
+
+## Git status before commit
+Only `local/validate-patches.R` was staged; `.superpowers/` remained untracked and was not committed.
+
+## Concerns
+The `vapply` call in the ambiguous-overlap check will crash (rather than report a clean validation error) when an entry is missing its `versions` field.
+The missing-field loop catches the schema error and populates `errs`, but the script reaches the `vapply` before printing those errors.
+Downstream tasks (B3/B4) may want to guard the `vapply` with a length/NULL check so the FAILED message is always printed cleanly.
+This was not changed here — the task required verbatim implementation of the brief.
+
+---
+
+## Fix: Null-safe key construction (commit `7e382c7`)
+
+### What changed
+In `local/validate-patches.R`, the `keys <- vapply(...)` block now uses `%||%` (base R 4.5.3) to substitute `"?"` for any NULL `e$package` or `e$versions`:
+
+```r
+keys <- vapply(reg, function(e) {
+  sprintf(
+    "%s|%s|%s",
+    e$package %||% "?",
+    paste(sort(as.character(unlist(e$platforms))), collapse = ","),
+    e$versions %||% "?"
+  )
+}, character(1L))
+```
+
+No other code changed (validation loop, error-print block, exit codes, messages all unchanged).
+
+### Verify: good registry (exit 0)
+```
+$ Rscript local/validate-patches.R; echo "exit=$?"
+Patch registry OK (1 entrie(s)).
+exit=0
+```
+
+### Verify: malformed registry (exit 1, no stacktrace)
+```
+$ cp local/patches/registry.json /tmp/reg.bak
+$ Rscript -e 'writeLines("[{\"package\":\"X\"}]", "local/patches/registry.json")'
+$ Rscript local/validate-patches.R; echo "exit=$?"
+Patch registry validation FAILED:
+  - entry 1 (X): missing versions, platforms, reason
+exit=1
+$ cp /tmp/reg.bak local/patches/registry.json
+registry restored
+```
+No R `Error in ...` / `Execution halted` stacktrace. Clean `validation FAILED` message with all collected errors printed before exit.