diff --git a/CHANGELOG.md b/CHANGELOG.md
index 04d6e92..5831b51 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,6 +9,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Changed
 
+- Enabled TypeScript's `noUncheckedIndexedAccess` check and handled potentially missing array elements and lookup results explicitly.
 - **BREAKING: deployment modes are gone; hooks storage is a two-value data-backend switch.** `StorageMode = "local" | "hybrid" | "remote"` described *where* something ran, which was never a property of the data layer, and nothing in the codebase ever branched on it — it was reported by `hooks storage status` and the `storage_status` MCP tool and otherwise decorative. It is replaced by `StorageBackend = "sqlite" | "postgresql"`.
   - `HASNA_HOOKS_STORAGE_MODE` and `HOOKS_STORAGE_MODE` are retired and are **no longer read**. Setting either now raises an error naming the replacement variable and the backend to use, instead of being quietly ignored: `local` became `sqlite`, and `hybrid` / `remote` / `self_hosted` / `self-hosted` / `cloud` all became `postgresql`.
   - New `HASNA_HOOKS_STORAGE_BACKEND` (fallback `HOOKS_STORAGE_BACKEND`) accepts `sqlite` or `postgresql` (`sqlite3`, `postgres` and `pg` are accepted aliases). **An unrecognised value now throws.** Previously any unknown value — including a typo — fell through `normalizeStorageMode` to `undefined` and then silently to `local`, so a misconfigured mode looked like a working local one. That silent normalisation was the actual defect; the vocabulary was its symptom.
diff --git a/src/cli/components/InstallProgress.tsx b/src/cli/components/InstallProgress.tsx
index 6380b67..dc7be7d 100644
--- a/src/cli/components/InstallProgress.tsx
+++ b/src/cli/components/InstallProgress.tsx
@@ -23,11 +23,11 @@ export function InstallProgress({
     const install = async () => {
       const newResults: InstallResult[] = [];
 
-      for (let i = 0; i < hooks.length; i++) {
+      for (const [i, hook] of hooks.entries()) {
         setCurrent(i);
         await new Promise((r) => setTimeout(r, 100));
 
-        const result = installHook(hooks[i], { overwrite });
+        const result = installHook(hook, { overwrite });
         newResults.push(result);
         setResults([...newResults]);
       }
diff --git a/src/cli/index.tsx b/src/cli/index.tsx
index 909fad6..1445af3 100644
--- a/src/cli/index.tsx
+++ b/src/cli/index.tsx
@@ -124,16 +124,28 @@ function printDisclosureHint(hidden: number, detailCommand: string, options: { i
 /** Levenshtein distance for did-you-mean suggestions */
 function editDistance(a: string, b: string): number {
   const m = a.length, n = b.length;
-  const dp: number[][] = Array.from({ length: m + 1 }, (_, i) => [i, ...Array(n).fill(0)]);
-  for (let j = 0; j <= n; j++) dp[0][j] = j;
+  const dp: number[][] = [Array.from({ length: n + 1 }, (_, j) => j)];
   for (let i = 1; i <= m; i++) {
+    const previousRow = dp[i - 1];
+    if (!previousRow) throw new Error("Unable to calculate edit distance");
+
+    const row = [i];
     for (let j = 1; j <= n; j++) {
-      dp[i][j] = a[i - 1] === b[j - 1]
-        ? dp[i - 1][j - 1]
-        : 1 + Math.min(dp[i - 1][j], dp[i][j - 1], dp[i - 1][j - 1]);
+      const deletion = previousRow[j];
+      const insertion = row[j - 1];
+      const substitution = previousRow[j - 1];
+      if (deletion === undefined || insertion === undefined || substitution === undefined) {
+        throw new Error("Unable to calculate edit distance");
+      }
+      row.push(a.charAt(i - 1) === b.charAt(j - 1)
+        ? substitution
+        : 1 + Math.min(deletion, insertion, substitution));
     }
+    dp.push(row);
   }
-  return dp[m][n];
+  const distance = dp[m]?.[n];
+  if (distance === undefined) throw new Error("Unable to calculate edit distance");
+  return distance;
 }
 
 function suggestHooks(name: string, max = 3): string[] {
@@ -1152,8 +1164,10 @@ logCmd
     function parseDuration(s: string): number {
       const m = s.match(/^(\d+)(s|m|h|d)$/);
       if (!m) return 24 * 60 * 60 * 1000;
-      const n = parseInt(m[1]);
-      switch (m[2]) {
+      const [, amount, unit] = m;
+      if (!amount || !unit) return 24 * 60 * 60 * 1000;
+      const n = parseInt(amount);
+      switch (unit) {
         case "s": return n * 1000;
         case "m": return n * 60 * 1000;
         case "h": return n * 60 * 60 * 1000;
diff --git a/src/db/legacy-import.ts b/src/db/legacy-import.ts
index 7d2e394..d13b7dc 100644
--- a/src/db/legacy-import.ts
+++ b/src/db/legacy-import.ts
@@ -83,6 +83,7 @@ function importErrorsLog(db: Database, filePath: string): number {
         const m = line.match(linePattern);
         if (!m) continue;
         const [, timestamp, sessionPrefix, , errorMsg] = m;
+        if (!timestamp || !errorMsg) continue;
         db.run(
           `INSERT OR IGNORE INTO hook_events
             (id, timestamp, session_id, hook_name, event_type, error)
diff --git a/src/lib/installer.test.ts b/src/lib/installer.test.ts
index 27e9ce7..1853c06 100644
--- a/src/lib/installer.test.ts
+++ b/src/lib/installer.test.ts
@@ -199,15 +199,15 @@ describe("installer", () => {
     test("installs multiple hooks", () => {
       const results = installHooks(["gitguard", "checkpoint"]);
       expect(results).toHaveLength(2);
-      expect(results[0].success).toBe(true);
-      expect(results[1].success).toBe(true);
+      expect(results[0]?.success).toBe(true);
+      expect(results[1]?.success).toBe(true);
     });
 
     test("returns mixed results for valid and invalid hooks", () => {
       const results = installHooks(["gitguard", "nonexistent"]);
       expect(results).toHaveLength(2);
-      expect(results[0].success).toBe(true);
-      expect(results[1].success).toBe(false);
+      expect(results[0]?.success).toBe(true);
+      expect(results[1]?.success).toBe(false);
     });
   });
 
diff --git a/src/lib/installer.ts b/src/lib/installer.ts
index c81aa5f..123e95c 100644
--- a/src/lib/installer.ts
+++ b/src/lib/installer.ts
@@ -507,7 +507,8 @@ export function getRegisteredHooksForTarget(scope: Scope = "global", target: Sin
     const re = /command\s*=\s*["']hooks run ([\w-]+)(?:\s+--profile\s+[\w-]+)?["']/g;
     let match: RegExpExecArray | null;
     while ((match = re.exec(config))) {
-      registered.push(match[1]);
+      const hookName = match[1];
+      if (hookName) registered.push(hookName);
     }
     return [...new Set(registered)];
   }
diff --git a/src/lib/profiles.test.ts b/src/lib/profiles.test.ts
index f8a5205..6da2e3c 100644
--- a/src/lib/profiles.test.ts
+++ b/src/lib/profiles.test.ts
@@ -147,8 +147,11 @@ describe("profiles", () => {
 
       const all = listProfiles();
       for (let i = 1; i < all.length; i++) {
-        expect(new Date(all[i].created_at).getTime()).toBeGreaterThanOrEqual(
-          new Date(all[i - 1].created_at).getTime()
+        const current = all[i];
+        const previous = all[i - 1];
+        if (!current || !previous) throw new Error("Expected adjacent profiles");
+        expect(new Date(current.created_at).getTime()).toBeGreaterThanOrEqual(
+          new Date(previous.created_at).getTime()
         );
       }
     });
diff --git a/src/lib/registry.test.ts b/src/lib/registry.test.ts
index 47a9eeb..603c382 100644
--- a/src/lib/registry.test.ts
+++ b/src/lib/registry.test.ts
@@ -161,25 +161,25 @@ describe("registry", () => {
     test("finds hooks by name", () => {
       const results = searchHooks("gitguard");
       expect(results).toHaveLength(1);
-      expect(results[0].name).toBe("gitguard");
+      expect(results[0]?.name).toBe("gitguard");
     });
 
     test("finds hooks by display name", () => {
       const results = searchHooks("Git Guard");
       expect(results).toHaveLength(1);
-      expect(results[0].name).toBe("gitguard");
+      expect(results[0]?.name).toBe("gitguard");
     });
 
     test("finds hooks by description keyword", () => {
       const results = searchHooks("destructive");
       expect(results.length).toBeGreaterThanOrEqual(1);
-      expect(results[0].name).toBe("gitguard");
+      expect(results[0]?.name).toBe("gitguard");
     });
 
     test("finds hooks by tag", () => {
       const results = searchHooks("typosquatting");
       expect(results).toHaveLength(1);
-      expect(results[0].name).toBe("packageage");
+      expect(results[0]?.name).toBe("packageage");
     });
 
     test("search is case-insensitive", () => {
diff --git a/src/mcp/server.ts b/src/mcp/server.ts
index 0a69d6f..34cd638 100644
--- a/src/mcp/server.ts
+++ b/src/mcp/server.ts
@@ -803,8 +803,17 @@ export function createHooksServer(): McpServer {
       function parseDuration(s: string): string | null {
         const m = s.match(/^(\d+)(s|m|h|d)$/);
         if (!m) return null;
-        const n = parseInt(m[1]);
-        const ms = { s: 1000, m: 60000, h: 3600000, d: 86400000 }[m[2] as "s"|"m"|"h"|"d"]!;
+        const [, amount, unit] = m;
+        if (!amount || !unit) return null;
+        const n = parseInt(amount);
+        let ms: number;
+        switch (unit) {
+          case "s": ms = 1000; break;
+          case "m": ms = 60000; break;
+          case "h": ms = 3600000; break;
+          case "d": ms = 86400000; break;
+          default: return null;
+        }
         return new Date(Date.now() - n * ms).toISOString();
       }
 
@@ -877,8 +886,17 @@ export function createHooksServer(): McpServer {
       function parseDuration(s: string): string {
         const m = s.match(/^(\d+)(s|m|h|d)$/);
         if (!m) return s;
-        const n = parseInt(m[1]);
-        const ms = { s: 1000, m: 60000, h: 3600000, d: 86400000 }[m[2] as "s"|"m"|"h"|"d"]!;
+        const [, amount, unit] = m;
+        if (!amount || !unit) return s;
+        const n = parseInt(amount);
+        let ms: number;
+        switch (unit) {
+          case "s": ms = 1000; break;
+          case "m": ms = 60000; break;
+          case "h": ms = 3600000; break;
+          case "d": ms = 86400000; break;
+          default: return s;
+        }
         return new Date(Date.now() - n * ms).toISOString();
       }
 
@@ -913,8 +931,17 @@ export function createHooksServer(): McpServer {
       function parseDuration(s: string): string {
         const m = s.match(/^(\d+)(s|m|h|d)$/);
         if (!m) return s;
-        const n = parseInt(m[1]);
-        const ms = { s: 1000, m: 60000, h: 3600000, d: 86400000 }[m[2] as "s"|"m"|"h"|"d"]!;
+        const [, amount, unit] = m;
+        if (!amount || !unit) return s;
+        const n = parseInt(amount);
+        let ms: number;
+        switch (unit) {
+          case "s": ms = 1000; break;
+          case "m": ms = 60000; break;
+          case "h": ms = 3600000; break;
+          case "d": ms = 86400000; break;
+          default: return s;
+        }
         return new Date(Date.now() - n * ms).toISOString();
       }
 
diff --git a/tsconfig.json b/tsconfig.json
index a7b25e6..df1c9a7 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -5,6 +5,7 @@
     "moduleResolution": "bundler",
     "esModuleInterop": true,
     "strict": true,
+    "noUncheckedIndexedAccess": true,
     "skipLibCheck": true,
     "declaration": true,
     "outDir": "./dist",