fix(refs): tighten inbox/saved thread URL routing

Only classify `t/{thread}` with an optional `c/{comment}` suffix after
inbox/saved; extra trailing segments stay unclassified so malformed URLs
aren't misrouted (e.g. as a conversation). Groups the branch by route
prefix and adds saved-thread + strictness test coverage.

Addresses review on #30.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: amix

src/lib/refs.test.ts

@@ -160,6 +160,11 @@ describe('parseCommsUrl', () => {
             'https://comms.todoist.com/12345/saved/t/TH1',
             { workspaceId: 12345, threadId: 'TH1' },
         ],
+        [
+            'saved thread with comment URL',
+            'https://comms.todoist.com/12345/saved/t/TH1/c/CM1',
+            { workspaceId: 12345, threadId: 'TH1', commentId: 'CM1' },
+        ],
         [
             'people URL as workspace-only',
             'https://comms.todoist.com/12345/people/u/678',
@@ -169,6 +174,18 @@ describe('parseCommsUrl', () => {
         expect(parseCommsUrl(url)).toEqual(expected)
     })
 
+    it('leaves inbox/saved URLs with extra trailing segments unclassified', () => {
+        // Only `t/{thread}[/c/{comment}]` is valid after inbox/saved; extra
+        // segments must not be misrouted (e.g. the trailing msg/CV1 as a
+        // conversation).
+        expect(parseCommsUrl('https://comms.todoist.com/12345/inbox/t/TH1/msg/CV1')).toEqual({
+            workspaceId: 12345,
+        })
+        expect(parseCommsUrl('https://comms.todoist.com/12345/saved/t/TH1/extra')).toEqual({
+            workspaceId: 12345,
+        })
+    })
+
     it('parses conversation URL', () => {
         const result = parseCommsUrl('https://comms.todoist.com/a/12345/msg/CV1')
         expect(result).toEqual({ workspaceId: 12345, conversationId: 'CV1' })
@@ -293,6 +310,11 @@ describe('resolveThreadId', () => {
             'inbox thread URL with comment suffix',
             'https://comms.todoist.com/12345/inbox/t/TH1/c/CM1',
         ],
+        ['saved thread URL', 'https://comms.todoist.com/12345/saved/t/TH1'],
+        [
+            'saved thread URL with comment suffix',
+            'https://comms.todoist.com/12345/saved/t/TH1/c/CM1',
+        ],
     ])('resolves %s', (_description, url) => {
         expect(resolveThreadId(url)).toBe('TH1')
     })

src/lib/refs.ts

@@ -135,12 +135,24 @@ export function parseCommsUrl(url: string): ParsedCommsUrl | null {
             }
         }
 
-        if (
-            (segments[routeStart] === 'inbox' || segments[routeStart] === 'saved') &&
-            segments[routeStart + 1] === 't'
-        ) {
-            parseRoutePairs(routeStart + 1)
-        } else if (segments[routeStart] !== 'inbox' && segments[routeStart] !== 'saved') {
+        const route = segments[routeStart]
+        if (route === 'inbox' || route === 'saved') {
+            // Inbox/saved thread URLs only carry `t/{thread}` with an optional
+            // `c/{comment}` suffix. Anything else (e.g. `inbox/done`, or extra
+            // trailing segments) stays unclassified so a malformed URL can't be
+            // misrouted — e.g. as a conversation.
+            const rest = segments.slice(routeStart + 1)
+            if (
+                rest[0] === 't' &&
+                rest[1] &&
+                (rest.length === 2 || (rest.length === 4 && rest[2] === 'c'))
+            ) {
+                result.threadId = rest[1]
+                if (rest.length === 4) {
+                    result.commentId = rest[3]
+                }
+            }
+        } else {
             parseRoutePairs(routeStart)
         }