diff --git a/agents/code-reviewer.md b/agents/code-reviewer.md
index 91cd7dc3..c0db2a22 100644
--- a/agents/code-reviewer.md
+++ b/agents/code-reviewer.md
@@ -27,6 +27,80 @@ When invoked:
 - **Consolidate** similar issues (e.g., "5 functions missing error handling" not 5 separate findings)
 - **Prioritize** issues that could cause bugs, security vulnerabilities, or data loss
 
+### Pre-Report Gate
+
+Before writing a finding, answer all four questions. If any answer is "no" or
+"unsure", downgrade severity or drop the finding.
+
+1. **Can I cite the exact line?** Name the file and line. Vague findings like
+   "somewhere in the auth layer" are not actionable and must be dropped.
+2. **Can I describe the concrete failure mode?** Name the input, state, and bad
+   outcome. If you cannot name the trigger, you are pattern-matching, not
+   reviewing.
+3. **Have I read the surrounding context?** Check callers, imports, and tests.
+   Many apparent issues are already handled one frame up or guarded by a type.
+4. **Is the severity defensible?** A missing JSDoc is never HIGH. A single
+   `any` in a test fixture is never CRITICAL. Severity inflation erodes trust
+   faster than missed findings.
+
+### HIGH / CRITICAL Require Proof
+
+For any finding tagged HIGH or CRITICAL, include:
+
+- The exact snippet and line number
+- The specific failure scenario: input, state, and outcome
+- Why existing guards, such as types, validation, or framework defaults, do not
+  catch it
+
+If you cannot produce all three, demote to MEDIUM or drop.
+
+### It Is Acceptable And Expected To Return Zero Findings
+
+A clean review is a valid review. Do not manufacture findings to justify the
+invocation. If the diff is small, well-typed, tested, and follows the project's
+patterns, the correct output is a summary with zero rows and verdict `APPROVE`.
+
+Manufactured findings, filler nits, speculative "consider using X", and
+hypothetical edge cases without a trigger are the primary failure mode of LLM
+reviewers and directly undermine this agent's usefulness.
+
+## Common False Positives - Skip These
+
+Patterns that LLM reviewers commonly mis-flag. Skip unless you have evidence
+specific to this codebase:
+
+- **"Consider adding error handling"** on a call whose error path is handled by
+  the caller or framework, such as Express error middleware, React error
+  boundaries, top-level `try/catch`, or Promise chains with `.catch` upstream.
+- **"Missing input validation"** when the function is internal and its callers
+  already validate. Trace at least one caller before flagging.
+- **"Magic number"** for well-known constants: `200`, `404`, `1000` ms, `60`,
+  `24`, `1024`, array index `0` or `-1`, HTTP status codes, and single-use
+  local constants whose meaning is obvious from the variable name.
+- **"Function too long"** for exhaustive `switch` statements, configuration
+  objects, test tables, or generated code. Length is not complexity.
+- **"Missing JSDoc"** on single-purpose internal helpers whose name and
+  signature are self-describing.
+- **"Prefer `const` over `let`"** when the variable is reassigned. Read the
+  whole function before flagging.
+- **"Possible null dereference"** when the preceding line narrows the type or an
+  `if` guard is in scope. Trace type flow instead of pattern-matching on `?.`.
+- **"N+1 query"** on fixed-cardinality loops, such as iterating a four-element
+  enum, or on paths already using `DataLoader` or batching.
+- **"Missing await"** on fire-and-forget calls that are intentionally detached,
+  such as logging, metrics, or background queue pushes. Check for a comment or
+  `void` prefix before flagging.
+- **"Should use TypeScript"** or **"Should have types"** in a JavaScript-only
+  file. Match the project's existing language; do not suggest a stack change.
+- **"Hardcoded value"** for values in test fixtures, example code, or
+  documentation snippets. Tests should have hardcoded expectations.
+- **Security theater**: flagging `Math.random()` in a non-cryptographic context
+  such as animation, jitter, or sampling, or flagging `eval`/`Function` in a
+  plugin system that is explicitly a code-loading surface.
+
+When tempted to flag one of the above, ask: "Would a senior engineer on this
+team actually change this in review?" If no, skip.
+
 ## Review Checklist
 
 ### Security (CRITICAL)
@@ -206,10 +280,13 @@ Verdict: WARNING — 2 HIGH issues should be resolved before merge.
 
 ## Approval Criteria
 
-- **Approve**: No CRITICAL or HIGH issues
+- **Approve**: No CRITICAL or HIGH issues, including clean reviews with zero
+  findings. This is a valid and expected outcome.
 - **Warning**: HIGH issues only (can merge with caution)
 - **Block**: CRITICAL issues found — must fix before merge
 
+Do not withhold approval to appear rigorous. If the diff is clean, approve it.
+
 ## Project-Specific Guidelines
 
 When available, also check project-specific conventions from `CLAUDE.md` or project rules:
diff --git a/docs/stale-pr-salvage-ledger.md b/docs/stale-pr-salvage-ledger.md
index c75721e3..67f727f3 100644
--- a/docs/stale-pr-salvage-ledger.md
+++ b/docs/stale-pr-salvage-ledger.md
@@ -44,6 +44,7 @@ on fresh branches, and credit the source PR.
 | #1566 | Agent architecture audit skill | Salvaged in #1772. |
 | #1578 | OpenCode file-probe hardening | Salvaged in #1773. |
 | #1603 | `plan-orchestrate` skill | Salvaged in #1766 with current manifest/catalog wiring. |
+| #1658 | Code-reviewer false-positive suppression | Salvaged in the May 12 code-reviewer maintainer pass with current review-agent wording, a proof gate for HIGH/CRITICAL findings, common false-positive exclusions, and a regression test. |
 | #1659 | Frontend design direction and interface-polish skills | Salvaged in the May 12 frontend-design maintainer pass with canonical `skills/` layout and current ECC frontend guidance, while preserving the repo guardrail that the official `frontend-design` skill should be installed from `anthropics/skills`. |
 | #1674 | Production audit skill | Salvaged in #1732 after supply-chain/privacy review and rewrite. |
 | #1687 | zh-CN localization sync | Large safe subsets salvaged in #1746-#1752; remaining pieces require translator/manual review. |
@@ -77,6 +78,8 @@ porting.
 | #1504 | Already mapped to #1776 in the durable salvage table. |
 | #1508 | Already present as `skills/fastapi-patterns/` and `agents/fastapi-reviewer.md`. |
 | #1603 | Useful `/plan-orchestrate` work was already preserved in #1766 with current package/catalog metadata. |
+| #1631 | Already present in `scripts/hooks/suggest-compact.js` and `tests/hooks/hooks.test.js`; current code reads `session_id` from stdin JSON before falling back to `CLAUDE_SESSION_ID`. |
+| #1658 | Ported through the code-reviewer maintainer branch after confirming the false-positive proof gate and common false-positive skip list were still missing. |
 | #1693 | Already present as `skills/redis-patterns/`. |
 
 ## Already Present Or Superseded
@@ -87,6 +90,7 @@ porting.
 | #1318 | Gemini agent adaptation utility was already present on current `main`. |
 | #1323 | Hook config update was already present on current `main`. |
 | #1337 | Catalog count update was superseded by current catalog-count sync. |
+| #1631 | `suggest-compact` stdin `session_id` isolation was already present on current `main` with hook tests. |
 | #1608 | Unsafe dashboard document/terminal open handling was already present on current `main` through safe runtime helpers and project-bound document opening. |
 | #1678 | Windows MCP `.cmd`/`.bat` fallback behavior was already present on current `main` with current health-check tests. |
 | #1682/#1701 | Strategic compact hook-path fixes were merged directly or superseded by current docs fixes. |
diff --git a/tests/ci/code-reviewer-false-positive-guard.test.js b/tests/ci/code-reviewer-false-positive-guard.test.js
new file mode 100644
index 00000000..935c8ed6
--- /dev/null
+++ b/tests/ci/code-reviewer-false-positive-guard.test.js
@@ -0,0 +1,82 @@
+#!/usr/bin/env node
+'use strict';
+
+const assert = require('assert');
+const fs = require('fs');
+const path = require('path');
+
+const repoRoot = path.resolve(__dirname, '..', '..');
+const reviewerPath = path.join(repoRoot, 'agents', 'code-reviewer.md');
+
+const requiredHeadings = [
+  '## Confidence-Based Filtering',
+  '### Pre-Report Gate',
+  '### HIGH / CRITICAL Require Proof',
+  '### It Is Acceptable And Expected To Return Zero Findings',
+  '## Common False Positives - Skip These',
+];
+
+const requiredPatterns = [
+  /Can I cite the exact line/i,
+  /concrete failure mode/i,
+  /Have I read the surrounding context/i,
+  /Severity inflation/i,
+  /exact snippet and line number/i,
+  /specific failure scenario/i,
+  /demote to MEDIUM or drop/i,
+  /clean review is a valid review/i,
+  /Manufactured findings/i,
+  /Common False Positives/i,
+  /Consider adding error handling/i,
+  /Missing input validation/i,
+  /Magic number/i,
+  /Would a senior engineer on this\s+team actually change this in review/i,
+  /Do not withhold approval to appear rigorous/i,
+];
+
+let passed = 0;
+let failed = 0;
+
+function test(name, fn) {
+  try {
+    fn();
+    console.log(`  PASS ${name}`);
+    passed++;
+  } catch (error) {
+    console.log(`  FAIL ${name}`);
+    console.log(`    Error: ${error.message}`);
+    failed++;
+  }
+}
+
+function readReviewer() {
+  return fs.readFileSync(reviewerPath, 'utf8');
+}
+
+console.log('\n=== Testing code-reviewer false-positive guardrails ===\n');
+
+for (const heading of requiredHeadings) {
+  test(`code-reviewer.md contains heading: ${heading}`, () => {
+    const source = readReviewer();
+    assert.ok(source.includes(heading), `code-reviewer.md missing required heading "${heading}"`);
+  });
+}
+
+for (const pattern of requiredPatterns) {
+  test(`code-reviewer.md matches ${pattern}`, () => {
+    const source = readReviewer();
+    assert.ok(pattern.test(source), `code-reviewer.md missing required pattern ${pattern}`);
+  });
+}
+
+test('code-reviewer.md retains the >80% confidence threshold', () => {
+  const source = readReviewer();
+  assert.ok(/>\s*80%\s*confident/i.test(source), 'code-reviewer.md missing >80% confidence threshold');
+});
+
+if (failed > 0) {
+  console.log(`\nFailed: ${failed}`);
+  process.exit(1);
+}
+
+console.log(`\nPassed: ${passed}`);
diff --git a/tests/docs/stale-pr-salvage-ledger.test.js b/tests/docs/stale-pr-salvage-ledger.test.js
index 24f407d5..e0ff5c0e 100644
--- a/tests/docs/stale-pr-salvage-ledger.test.js
+++ b/tests/docs/stale-pr-salvage-ledger.test.js
@@ -58,6 +58,7 @@ test('stale PR salvage ledger preserves representative source attribution', () =
     '#1493',
     '#1528/#1529/#1547',
     '#1603',
+    '#1658',
     '#1659',
     '#1674',
     '#1687',
@@ -110,6 +111,8 @@ test('stale PR salvage ledger records the May 12 gap pass', () => {
     '#1504',
     '#1508',
     '#1603',
+    '#1631',
+    '#1658',
     '#1693',
   ]) {
     assert.ok(source.includes(pr), `Missing May 12 gap-pass PR ${pr}`);
@@ -119,6 +122,8 @@ test('stale PR salvage ledger records the May 12 gap pass', () => {
   assert.ok(source.includes('already preserved in #1770'));
   assert.ok(source.includes('already preserved in #1769'));
   assert.ok(source.includes('already preserved in #1766'));
+  assert.ok(source.includes('false-positive proof gate'));
+  assert.ok(source.includes('session_id` from stdin JSON'));
   assert.ok(source.includes('Already present as `skills/redis-patterns/`'));
 });