diff --git a/.github/workflows/quality.yml b/.github/workflows/quality.yml
index f3f5fa0a1e..7a167afcd0 100644
--- a/.github/workflows/quality.yml
+++ b/.github/workflows/quality.yml
@@ -155,7 +155,18 @@ jobs:
       - run: npm run check:fetch-targets
       # docs-all / openapi-routes / docs-symbols live in docs-gates (path-filtered).
       - run: npm run check:deps
-      - run: npm run check:file-size
+      # #8522: --base-ref mode for PR events — compare against max(frozen, base) so
+      # inherited drift (base already over frozen cap) doesn't red an innocent PR.
+      # workflow_dispatch (no PR base) falls back to absolute comparison.
+      - name: File-size ratchet (base-relative on PR)
+        env:
+          PR_BASE_SHA: ${{ github.event.pull_request.base.sha }}
+        run: |
+          if [ -n "$PR_BASE_SHA" ]; then
+            npm run check:file-size -- --base-ref "$PR_BASE_SHA"
+          else
+            npm run check:file-size
+          fi
       - run: npm run check:error-helper
       - run: npm run check:migration-numbering
       - run: npm run check:public-creds
diff --git a/changelog.d/fixes/8522-fix.plan.md b/changelog.d/fixes/8522-fix.plan.md
new file mode 100644
index 0000000000..41a25b266b
--- /dev/null
+++ b/changelog.d/fixes/8522-fix.plan.md
@@ -0,0 +1 @@
+- fix(quality): add base-relative file-size check so inherited drift does not red innocent PRs (#8522)
diff --git a/changelog.d/maintenance/basereds-eslint-baseline-tighten.md b/changelog.d/maintenance/basereds-eslint-baseline-tighten.md
new file mode 100644
index 0000000000..d2085f85c9
--- /dev/null
+++ b/changelog.d/maintenance/basereds-eslint-baseline-tighten.md
@@ -0,0 +1 @@
+- fix(quality): tighten eslintWarnings baseline 5000->0 to match the gate's suppressions-applied measurement (unblocks require-tighten on every code PR)
diff --git a/config/quality/eslint-suppressions.json b/config/quality/eslint-suppressions.json
index e20f17c04c..b25bdbca91 100644
--- a/config/quality/eslint-suppressions.json
+++ b/config/quality/eslint-suppressions.json
@@ -1,5 +1,4 @@
 {
-  "_comment": "Congelamento em massa gerado em 2026-08-05 durante a migracao para TypeScript 7 (branch release/v3.8.50). A mudanca de toolchain elevou a contagem de violacoes ESLint de forma ampla e mecanica: 4344 violacoes em 676 arquivos, concentradas em @typescript-eslint/no-explicit-any (4063) e no-restricted-imports (203). Todas sao PRE-EXISTENTES ao congelamento - nenhuma foi introduzida para passar o gate. Politica (CLAUDE.md): novas violacoes DEVEM ser corrigidas, nunca adicionadas aqui; esta allowlist so cobre a divida herdada da migracao. As entradas devem ser reduzidas conforme a divida for paga (o gate quality-ratchet impede crescimento). Regenerado a partir de `npx eslint . --format json`; entradas individuais nao levam justificativa propria por serem de origem unica e mecanica - a justificativa e esta.",
   "open-sse/executors/blackbox-web.ts": {
     "@typescript-eslint/no-explicit-any": {
       "count": 1
@@ -1292,11 +1291,6 @@
       "count": 1
     }
   },
-  "src/lib/usage/providerLimits.ts": {
-    "no-restricted-imports": {
-      "count": 1
-    }
-  },
   "src/lib/usage/providerWindowCosts.ts": {
     "no-restricted-syntax": {
       "count": 1
@@ -3388,4 +3382,4 @@
       "count": 5
     }
   }
-}
+}
\ No newline at end of file
diff --git a/config/quality/quality-baseline.json b/config/quality/quality-baseline.json
index e0795368ec..aac7ef514a 100644
--- a/config/quality/quality-baseline.json
+++ b/config/quality/quality-baseline.json
@@ -2,9 +2,9 @@
   "_comment": "Catraca de qualidade. 'down' = nao pode aumentar; 'up' = nao pode cair. Atualize via 'npm run quality:ratchet -- --update' (somente quando melhora). Cada valor e um numero REAL medido, nunca um chute. Cobertura entra na Fase 4 a partir de um run de cobertura mergeada no CI.",
   "metrics": {
     "eslintWarnings": {
-      "value": 5000,
+      "value": 0,
       "direction": "down",
-      "_rebaseline_2026_08_05_ts7_migration": "Rebaseline para 5000 (direction: down) em 2026-08-05 por conta da migracao para TypeScript 7 na release/v3.8.50. A mudanca de toolchain elevou a contagem de warnings de forma ampla e mecanica. Medicao no tip: 4139 warnings (folga de ~860 para o teto). A divida esta congelada em config/quality/eslint-suppressions.json (ver _comment la). Apertar via `npm run quality:ratchet -- --update` conforme a divida for paga."
+      "_rebaseline_2026_08_05_post_prune": "Apertado 5000->0 em 2026-08-05: o gate mede via lint:json COM as suppressions aplicadas (config/quality/eslint-suppressions.json congela a divida da migracao TS7), entao a contagem real do gate e 0. O 5000 anterior foi medido SEM suppressions (4139 brutos) e fazia o require-tighten reprovar todo PR de codigo (delta 5000>slack). Divida TS7 continua rastreada nas suppressions; warning NOVO (fora delas) agora e red imediato, que e a politica."
     },
     "eslintErrors": {
       "value": 0,
diff --git a/scripts/check/check-file-size.mjs b/scripts/check/check-file-size.mjs
index 3a3cc3a2d0..4bfc87a7a5 100644
--- a/scripts/check/check-file-size.mjs
+++ b/scripts/check/check-file-size.mjs
@@ -11,6 +11,7 @@
 // igual ao próprio teto ficava presa no baseline para sempre — ver #8584.
 import fs from "node:fs";
 import path from "node:path";
+import { execFileSync } from "node:child_process";
 import { pathToFileURL } from "node:url";
 
 const ROOT = process.cwd();
@@ -22,6 +23,7 @@ const BASELINE_PATH = path.resolve(
   getArg("--baseline", path.join(ROOT, "config/quality/file-size-baseline.json"))
 );
 const UPDATE = process.argv.includes("--update");
+const BASE_REF = getArg("--base-ref"); // SHA for PR base-relative mode (#8522)
 const SCAN_DIRS = ["src", "open-sse", "electron", "bin"];
 // Test files live under tests/ plus co-located *.test.ts(x) inside the source dirs.
 const TEST_SCAN_DIRS = ["tests", ...SCAN_DIRS];
@@ -37,20 +39,39 @@ const SKIP_DIRS = new Set(["node_modules", "dist-electron", ".next", ".build", "
  * (loc < frozen), entao uma entrada igual ao proprio teto nunca saia da lista,
  * por mais abaixo do cap que estivesse (3 casos reais no v3.8.49).
  *
+ * Quando `baseLocByFile` e fornecido (modo PR), a violacao e computada contra
+ * o MAIOR entre o valor congelado e o valor na base -- assim um PR inocente
+ * (head === base no arquivo) nao e penalizado por drift herdado (#8522).
+ *
+ * @param {Object} currentLocByFile — LOC atuais (head)
+ * @param {Object} frozen — baseline congelado
+ * @param {number} cap — teto para arquivos novos
+ * @param {Object} [baseLocByFile] — LOC na branch base (opcional, modo PR)
  * @returns {{violations: string[], improvements: [string, number][], redundant: string[]}}
  */
-export function evaluateFileSizes(currentLocByFile, frozen, cap) {
+export function evaluateFileSizes(currentLocByFile, frozen, cap, baseLocByFile) {
   const violations = [];
   const improvements = [];
   const redundant = [];
   for (const [file, loc] of Object.entries(currentLocByFile)) {
     if (file in frozen) {
-      if (loc > frozen[file])
+      const threshold = baseLocByFile
+        ? Math.max(frozen[file], baseLocByFile[file] ?? frozen[file])
+        : frozen[file];
+      if (loc > threshold)
         violations.push(`${file}: ${loc} > congelado ${frozen[file]} (não pode crescer)`);
       else if (loc < frozen[file]) improvements.push([file, loc]);
       else if (loc <= cap) redundant.push(file);
     } else if (loc > cap) {
-      violations.push(`${file}: ${loc} > cap ${cap} (arquivo novo acima do limite)`);
+      if (!baseLocByFile) {
+        violations.push(`${file}: ${loc} > cap ${cap} (arquivo novo acima do limite)`);
+      } else {
+        // Modo PR: so viola se cresceu alem do que ja estava na base
+        const baseLoc = baseLocByFile[file] ?? 0;
+        const prThreshold = Math.max(cap, baseLoc);
+        if (loc > prThreshold)
+          violations.push(`${file}: ${loc} > cap ${cap} (arquivo novo acima do limite)`);
+      }
     }
   }
   return { violations, improvements, redundant };
@@ -108,6 +129,30 @@ function collectTestLoc() {
   return out;
 }
 
+/**
+ * Computa LOC por arquivo a partir de um ref git (branch, SHA, tag).
+ * Usado pelo modo --base-ref para obter a contagem na base do PR (#8522).
+ * @param {string} ref — git ref (e.g. SHA da branch base)
+ * @param {string[]} files — lista de paths relativos ao ROOT
+ * @returns {Object} mapa file → line count
+ */
+function getBaseLoc(ref, files) {
+  const out = {};
+  for (const file of files) {
+    try {
+      const buf = execFileSync("git", ["show", `${ref}:${file}`], {
+        encoding: "utf8",
+        stdio: ["ignore", "pipe", "ignore"],
+        timeout: 5000,
+      });
+      out[file] = buf.split("\n").length;
+    } catch {
+      // Arquivo nao existe na base (novo no PR) — tratado como 0
+    }
+  }
+  return out;
+}
+
 function main() {
   if (!fs.existsSync(BASELINE_PATH)) {
     console.error(`[file-size] FAIL — ${path.basename(BASELINE_PATH)} ausente.`);
@@ -117,7 +162,17 @@ function main() {
   const cap = baseline.cap;
   const frozen = baseline.frozen || {};
   const current = collectLoc();
-  const { violations, improvements, redundant } = evaluateFileSizes(current, frozen, cap);
+
+  // Modo PR: computa LOC na branch base para comparacao relativa (#8522)
+  const baseLoc = BASE_REF ? getBaseLoc(BASE_REF, Object.keys(current)) : undefined;
+  if (BASE_REF) {
+    const baseKeys = Object.keys(baseLoc).length;
+    console.log(
+      `[file-size] modo PR (--base-ref ${BASE_REF.slice(0, 12)}): ${baseKeys} arquivos da base computados`
+    );
+  }
+
+  const { violations, improvements, redundant } = evaluateFileSizes(current, frozen, cap, baseLoc);
 
   // Test-file gate (Layer 1 anti-reinflation): same shrink-only + new-≤cap semantics,
   // reusing evaluateFileSizes against the testFrozen baseline + testCap.
@@ -129,7 +184,7 @@ function main() {
     improvements: testImprovements,
     redundant: testRedundant,
   } = typeof testCap === "number"
-    ? evaluateFileSizes(currentTests, testFrozen, testCap)
+    ? evaluateFileSizes(currentTests, testFrozen, testCap, BASE_REF ? baseLoc : undefined)
     : { violations: [], improvements: [], redundant: [] };
 
   if (UPDATE) {
diff --git a/tests/unit/repro-8522.test.ts b/tests/unit/repro-8522.test.ts
index c6d4dd6c30..c122bf3807 100644
--- a/tests/unit/repro-8522.test.ts
+++ b/tests/unit/repro-8522.test.ts
@@ -25,21 +25,22 @@ test("8522: innocent PR (base already over frozen cap) must NOT be a violation",
   const frozen = { "src/foo.ts": 100 };
   const cap = 100;
 
-  const { violations } = evaluateFileSizes(currentLocByFile, frozen, cap);
+  // With baseLocByFile, the gate compares against max(frozen, base) = max(100, 110) = 110,
+  // so 110 > 110 is false — innocent PR passes.
+  const { violations } = evaluateFileSizes(currentLocByFile, frozen, cap, baseLocByFile);
 
-  // The gate has no base-ref input; it compares head LOC (110) to frozen (100)
-  // and flags a violation. But the PR introduced ZERO growth — it is a false
-  // positive on inherited drift.
   assert.deepEqual(violations, [], "innocent PR flagged for inherited drift");
 });
 
 test("8522: PR that DOES grow a frozen file above frozen cap is a violation", () => {
   // Sanity: the gate must still catch a PR that grows the file above its cap.
+  // Base is at the frozen cap (100), but PR grew it to 112.
   const baseLocByFile = { "src/foo.ts": 100 };
   const currentLocByFile = { "src/foo.ts": 112 }; // PR grew it +12
   const frozen = { "src/foo.ts": 100 };
   const cap = 100;
 
-  const { violations } = evaluateFileSizes(currentLocByFile, frozen, cap);
+  // With baseLocByFile: threshold = max(100, 100) = 100, 112 > 100 → violation
+  const { violations } = evaluateFileSizes(currentLocByFile, frozen, cap, baseLocByFile);
   assert.equal(violations.length, 1, "own-growth PR must be a violation");
 });