diff --git a/dev-docs/BACKLOG.md b/dev-docs/BACKLOG.md
index c1841ad4..0756d2ca 100644
--- a/dev-docs/BACKLOG.md
+++ b/dev-docs/BACKLOG.md
@@ -987,54 +987,77 @@ tamperbaar door lokale users, dus dit is ook een kleine security
 verbetering.
 **Prioriteit:** Laag — defensive hardening, geen user-impact.
 
-### TECH-TS-PORTAL-TSC — `tsc --noEmit` baseline reduction (apps/portal)
+### ~~TECH-TS-PORTAL-TSC — `tsc --noEmit` baseline reduction (apps/portal)~~
 
-**Priority:** medium → **high before S3b organizer UI lands.**
-**Scope:** 22 pre-existing TypeScript errors in `apps/portal/src/`
-own code surfaced by foundation-tooling commit 3 (ts-reset install).
+**Status: closed 2026-04-25** — `pnpm exec vue-tsc --noEmit` exits
+clean in `apps/portal/`. Sprint commits: `f7bb864` (tiptap 2.27.2
+upgrade) + `a7ccd2b` (4 long-tail fixes).
 
-**Trigger to upgrade priority to "must-fix-now":** any S3b
-form-builder organizer UI commit. Launching new TypeScript code on
-top of an unverified existing-error baseline produces unactionable
-compile output ("which errors are mine?"). Reduce to zero before
-S3b starts.
+**Correction to the original framing:** the entry initially read
+"22 pre-existing tsc errors in own code + 4 in tiptap node_modules".
+The "4" was the **delta** that ts-reset added in foundation-tooling
+commit 3 (ts-reset's `JSON.parse → unknown` tightening surfaced 4
+new tiptap errors), **not** the absolute pre-existing tiptap baseline.
+The actual absolute count was **~707 tiptap node_modules errors**,
+silently invisible because the project's CI runs build + vitest only,
+not `vue-tsc`.
 
-**Triage approach (mirror Larastan reduction pattern):**
-1. `cd apps/portal && pnpm exec vue-tsc --noEmit 2>&1 | grep "src/" > /tmp/tsc-errors.txt`
-2. Group by error code (TS2339 property-not-found, TS2345 argument
-   type, TS18047 possibly null, TS2322 not-assignable, etc.) —
-   typical top categories on a Vue-3 + Pinia codebase. Foundation-
-   tooling triage already noted clusters in TiptapEditor/
-   ProductDescriptionEditor commands, a `@iconify/types` missing
-   import, and a themeConfig `Lowercase<string>` mismatch
-3. Fix per-category in scoped commits (mirror Larastan reduction
-   sprints — one category per PR if >5 occurrences, combine if <=5)
-4. Add `pnpm exec vue-tsc --noEmit` to a pre-commit hook or CI as
-   blocking gate once own-code errors hit zero (CI integration is
-   tracked separately; the gate enforcement is what closes the
-   "new code introduces no new errors" discipline gap)
+**Root cause of the 707:** tiptap 2.27.1's `dist/index.d.ts`
+re-exported from `'../src/CommandManager.js'` and ~22 similar lines
+that referenced `.js` files which did not exist (only `.ts` source).
+With `moduleResolution: "Bundler"`, vue-tsc fell through and pulled
+tiptap's entire uncompiled source tree into the program. Tiptap
+2.27.2 (a patch release) fixed the dist exports to use sibling-
+relative paths (`./CommandManager.js`) that resolve correctly to
+the existing `dist/*.d.ts` siblings.
 
-**Tiptap upstream errors (4 in node_modules):**
-`skipLibCheck: true` is **already set** in both SPAs' `tsconfig.json`
-(only one tsconfig variant exists per SPA; no `tsconfig.app.json`
-or `tsconfig.node.json` split). Despite that, the 4 errors persist
-because **tiptap ships uncompiled `.ts` source files** in
-`node_modules/.../@tiptap/core/src/`, not `.d.ts` declaration
-files. `skipLibCheck` only suppresses checking of `.d.ts` files;
-it does **not** apply to raw `.ts` files that vue-tsc pulls in
-through the import graph. Real options, in order of preference:
-(a) upgrade `@tiptap/*` to a release that ships only `.d.ts`
-(check upstream — the policy may already have changed in newer
-majors); (b) add a focused `exclude` glob for tiptap's
-`node_modules/.../src/**/*.ts` if the upgrade is blocked. Avoid
-blanket `node_modules` excludes — they can break import resolution
-in vue-tsc.
+**Why `skipLibCheck` did not help:** `skipLibCheck: true` was
+already set in `apps/portal/tsconfig.json` (and `apps/app/`)
+**but only suppresses checking of `.d.ts` declaration files**.
+Tiptap's uncompiled `.ts` source files in `node_modules/.../src/`
+were raw `.ts`, not `.d.ts`, so they bypassed `skipLibCheck` once
+the import graph reached them. The 2.27.2 packaging fix made the
+import graph stop there, no exclusion needed.
 
-**Out of scope:** runtime fixes for behaviors that surface as type
-errors but aren't actually broken at runtime. If a fix requires
-reasoning about runtime behavior (not just type narrowing), surface
-it as a separate ticket — TypeScript-correctness is this sprint's
-remit, runtime-correctness is a different concern.
+**Final error tally:**
+- Pre: 729 vue-tsc errors (~22 own-code, of which 18 were TS2339
+  downstream of tiptap's broken types; ~707 in node_modules/@tiptap)
+- Post-tiptap-upgrade: 4 own-code (the tiptap-independent stragglers:
+  `vite.config.ts` TS7006, `themeConfig.ts` TS2322 via
+  `LayoutConfig.title` `Lowercase<string>` over-constraint,
+  `build-icons.ts` TS2307 missing `@iconify/types`,
+  `casl.ts` TS2345 vue-router meta cast)
+- Post-long-tail-fixes: 0 own-code, 0 node_modules
+
+**Aftermath:**
+- The S3b form-builder organizer UI now lands on a verified
+  zero-error baseline.
+- The "new code introduces no new errors" discipline still depends
+  on a CI gate — see TECH-PORTAL-TSC-CI-GATE follow-up.
+
+### TECH-PORTAL-TSC-CI-GATE — vue-tsc as a blocking gate for apps/portal
+
+**Aanleiding:** TECH-TS-PORTAL-TSC reached zero in commits `f7bb864`
++ `a7ccd2b`, but the project has no pre-commit infrastructure
+(no husky, lefthook, or simple-git-hooks) and CI does not run
+`vue-tsc` either. Without a blocking gate, the baseline can drift
+back to non-zero between commits — exactly the discipline gap
+that produced the 22 pre-existing errors in the first place.
+**Wat:**
+- Add `pnpm exec vue-tsc --noEmit` as a CI step in the workflow that
+  runs portal build/vitest (most natural location).
+- OR introduce a pre-commit infrastructure (lefthook is lighter than
+  husky for monorepos) and run vue-tsc on portal-touching commits.
+- Either path: the gate must fail the run on any new vue-tsc error
+  in `apps/portal/`.
+**Out of scope:** extending the same gate to `apps/app/` — that
+SPA still has a different mix of errors and would be a separate
+sprint (out of scope today, would land alongside TECH-APP-VITEST or
+later).
+**Prioriteit:** Middel — without the gate, TECH-TS-PORTAL-TSC's
+zero state has no enforcement. Should land before S3b organizer UI
+work to keep that sprint's "new code introduces no new errors"
+discipline mechanically enforceable.
 
 ### TECH-APP-VITEST — apps/app Vitest setup