📋 Issue 1: Individual Copy-to-Clipboard Buttons for Action Items and Decisions #352

### Description
Currently, Late-Meet allows users to copy the entire meeting summary to the clipboard via the dropdown menu. However, users often want to copy only a single action item or a single key decision to quickly share it with their team in Slack, Microsoft Teams, or a ticket tracker (like Jira).

We should add a subtle, elegant "Copy" button next to each action item and decision listed in the dashboard side panel.

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### Proposed Solution / Technical Guidance
1. **Render Copy Buttons**:
   - Locate the rendering loops in `src/dashboard.ts`. 
   - In `updateActionItems(actionItems, meetingId)`, within the loop creating the action item elements, append a copy button (using a clean SVG clipboard icon).
   - In `updateDecisions(decisions)` (or the respective decisions list rendering block), append a similar copy button next to the decision text.
2. **Handle Click Event**:
   - Wire up click listeners to these buttons that invoke `navigator.clipboard.writeText` to copy the formatted text.
   - For action items, copy a format like: `[ ] [Task] - Assignee: [Owner] (Due: [Deadline])`.
   - For decisions, copy a format like: `[Decision] - Announced by: [By]`.
3. **Show Toast/Tooltip**:
   - Trigger a temporary tooltip or leverage the existing `showToast("Copied to clipboard!", "success")` function from `src/dashboard.ts` to provide immediate visual feedback.
4. **Style the Icons**:
   - Ensure the copy buttons use smooth transitions, hover effects, and align beautifully with the monochrome glassmorphism aesthetic specified in `src/dashboard.css`.

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### Files to Modify
- `src/dashboard.ts` (specifically action items & decisions update rendering loops)
- `src/dashboard.css` (for copy-button positioning and hover animations)

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### Definition of Done
- [ ] Subtle clipboard SVG icons appear next to each individual action item and decision.
- [ ] Clicking the icon copies that specific item in a clean text format to the system clipboard.
- [ ] A success toast or tooltip is triggered on click.
- [ ] The feature operates perfectly in both light and dark/system themes without breaking layout alignment.