• Replace localStorage with sessionStorage for message history
• Remove conversationId field from stored user messages
• Simplify message initialization to use only current conversation
• Reduce storage complexity by eliminating cross-conversation message tracking

Switch message storage from localStorage to sessionStorage

• Replace all localStorage calls with sessionStorage for conversation user messages
• Updates reset(), get(), and put() methods in createConversationUserMessageStore
• Changes storage mechanism from persistent to session-based

src/lib/helpers/store.js

Simplify message handling to current conversation only

• Remove conversationId field from user message objects in initUserSentMessages()
• Simplify message initialization to only process current conversation messages
• Remove logic that filters and merges messages from other conversations
• Update renewUserSentMessages() to exclude conversationId from new messages

src/routes/chat/[agentId]/[conversationId]/chat-box.svelte

Description

• conversationUserMessageStore.get() parses session storage content without any try/catch, so
  malformed or tampered storage data can throw and crash the chat flow.
• Accessing sessionStorage itself can also throw in restricted browser contexts (privacy modes,
  disabled storage), and there is no graceful fallback.
• This violates the requirement to explicitly handle failure points and validate external inputs
  before use.

Code

src/lib/helpers/store.js[R246-252]

        get: () => {
-            const json = localStorage.getItem(conversationUserMessageKey);
+            const json = sessionStorage.getItem(conversationUserMessageKey);
            return json ? JSON.parse(json) : {};
        },
        put: (value) => {
-            localStorage.setItem(conversationUserMessageKey, JSON.stringify(value));
+            sessionStorage.setItem(conversationUserMessageKey, JSON.stringify(value));
        }

Evidence

The compliance checklist requires robust handling of failure points and explicit validation of
external inputs. The updated code reads from sessionStorage and directly executes
JSON.parse(json) with no exception handling or validation, which can raise runtime exceptions from
malformed content or unavailable storage.

Rule 3: Generic: Robust Error Handling and Edge Case Management
Rule 6: Generic: Security-First Input Validation and Data Handling
src/lib/helpers/store.js[241-252]

Agent prompt

The issue below was found during a code review. Follow the provided context and guidance below and implement a solution

## Issue description
`conversationUserMessageStore.get()` directly calls `JSON.parse` on data read from `sessionStorage` without error handling or validation. This can throw on malformed/tampered storage values or when `sessionStorage` is unavailable, leading to runtime crashes.

## Issue Context
Session storage is user-controllable and can be corrupted; browser storage APIs can also throw (e.g., blocked/disabled storage). The code should degrade gracefully and avoid propagating exceptions.

## Fix Focus Areas
- src/lib/helpers/store.js[241-252]

ⓘ Copy this prompt and use it to remediate the issue with your preferred AI generation tools

Description

• renewUserSentMessages() spreads savedMessages?.messages into an array without validating it is
  an array/iterable, so corrupted session data can cause a TypeError and break message history.
• Because the stored value comes from browser storage (external/user-controllable), it should be
  schema-validated (e.g., ensure messages is an array of {text} objects) before use.
• This violates the requirement for input validation and explicit edge-case handling for
  null/invalid values.

Code

src/routes/chat/[agentId]/[conversationId]/chat-box.svelte[R406-409]

	function renewUserSentMessages(msg) {
		const savedMessages = conversationUserMessageStore.get();
-		const allMessages = [...savedMessages?.messages || [], { conversationId: params.conversationId, text: msg || '' }];
+		const allMessages = [...savedMessages?.messages || [], { text: msg || '' }];
		const trimmedMessages = trimUserSentMessages(allMessages);

Evidence

The compliance checklist requires validation of external inputs and handling of edge cases. Here,
data loaded from storage is assumed to have an iterable messages field and is spread into a new
array without type checks, which can throw if the stored structure is corrupted or unexpected.

Rule 6: Generic: Security-First Input Validation and Data Handling
Rule 3: Generic: Robust Error Handling and Edge Case Management
src/routes/chat/[agentId]/[conversationId]/chat-box.svelte[405-409]

Agent prompt

The issue below was found during a code review. Follow the provided context and guidance below and implement a solution

## Issue description
`renewUserSentMessages()` assumes `savedMessages.messages` is iterable and spreads it without validating its type/shape. If storage data is malformed, this can throw and break the UI.

## Issue Context
Data retrieved from browser storage should be treated as untrusted/external input and validated before use.

## Fix Focus Areas
- src/routes/chat/[agentId]/[conversationId]/chat-box.svelte[405-425]

ⓘ Copy this prompt and use it to remediate the issue with your preferred AI generation tools

Description

• conversationUserMessageStore now writes/reads only from sessionStorage, so any existing
  localStorage['conversation_user_messages'] created by prior versions becomes orphaned data.
• resetStorage() does not remove this legacy localStorage key (it only clears localStorage keys
  starting with "message"), so old conversation message history can persist indefinitely on the
  device.
• This is primarily a reliability/data-hygiene issue (stale storage growth) and may undermine the
  purpose of moving message history to session-scoped storage.

Code

src/lib/helpers/store.js[R244-252]

+            sessionStorage.removeItem(conversationUserMessageKey);
        },
        get: () => {
-            const json = localStorage.getItem(conversationUserMessageKey);
+            const json = sessionStorage.getItem(conversationUserMessageKey);
            return json ? JSON.parse(json) : {};
        },
        put: (value) => {
-            localStorage.setItem(conversationUserMessageKey, JSON.stringify(value));
+            sessionStorage.setItem(conversationUserMessageKey, JSON.stringify(value));
        }

Evidence

The store now exclusively uses sessionStorage for the conversation_user_messages key, while the
project’s reset path only clears sessionStorage via conversationUserMessageStore.reset() and clears
localStorage keys with prefix "message"—which does not match "conversation_user_messages".
Therefore, any pre-existing localStorage entry for conversation_user_messages will never be removed
by these flows.

src/lib/helpers/store.js[7-12]
src/lib/helpers/store.js[241-253]
src/lib/helpers/store.js[295-306]
src/lib/helpers/store.js[308-323]

Agent prompt

The issue below was found during a code review. Follow the provided context and guidance below and implement a solution

### Issue description
`conversationUserMessageStore` migrated from `localStorage` to `sessionStorage`. Any existing `localStorage['conversation_user_messages']` created by older versions will no longer be touched, and current reset flows do not remove it.

### Issue Context
The app calls `resetStorage()` in multiple user flows (e.g., login/logout). `resetStorage()` clears only `sessionStorage` for the new store and clears localStorage keys with prefix `message`, which does not match `conversation_user_messages`.

### Fix Focus Areas
- src/lib/helpers/store.js[241-256]
- src/lib/helpers/store.js[295-306]
- src/lib/helpers/store.js[308-323]

### Implementation notes
- In `resetStorage()`, add `localStorage.removeItem(conversationUserMessageKey)` (guarded by `browser` if needed).
- Optionally add a one-time migration cleanup on module load (browser-only) to delete the legacy localStorage key even if `resetStorage()` is never called.

ⓘ Copy this prompt and use it to remediate the issue with your preferred AI generation tools