[decompose] extract helpers from js/ui/profileModalController.js

Extracted DM Relay UI logic and DM Attachment logic into separate binder modules to reduce the size of ProfileModalController.js. Updated file size baseline.

Co-authored-by: PR0M3TH3AN <[email protected]>

context/CONTEXT_1739837127.md

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+# Decompose: js/ui/profileModalController.js
+
+## Selection
+Selected `js/ui/profileModalController.js` (6258 lines) because it is the largest grandfathered file not decomposed in the last 8 weeks.
+
+## Plan
+Extract two cohesive blocks related to DM functionality that are currently mixed into the main controller:
+
+1. **DM Relay UI Logic** (`ProfileDmRelayBinder.js`)
+   - `cacheDmRelayElements`
+   - `bindDmRelayControls`
+   - `refreshDmRelayPreferences`
+   - `handlePublishDmRelayPreferences`
+   - `updateDmPrivacyToggleForRecipient`
+   - `setPrivacyToggleState`
+   - `handleActiveDmIdentityChanged`
+
+2. **DM Attachment Logic** (`ProfileDmAttachmentBinder.js`)
+   - `renderAttachmentQueue`
+   - `uploadAttachmentQueue`
+   - `resolveLatestDirectMessageForRecipient`
+   - `maybePublishTypingIndicator`
+
+These functions heavily rely on `this.dmController` and `this.services`, suggesting they belong in dedicated helpers or the DM controller itself. Extracting them to binder modules allows preserving the `this` context via argument passing while reducing the main file size.
+
+## Stats
+- Original size: 6258 lines
+- Target reduction: > 200 lines