fix: Move feedback widget to nav bar bug icon (#159)

[deucebucket]

Summary

• Removed the floating feedback button (fixed bottom-right corner) from base.html
• Added a bug icon (bi-bug) to the top navigation bar that triggers the existing showFeedbackModal() function
• All feedback modals, error auto-reporting, toast notifications, and JS functions remain unchanged

Closes #159

[bucket-agent]

🔍 Vibe Check Review

Context

Moves the feedback/bug-report trigger from a fixed floating button (bottom-right) to a bi-bug icon in the top navigation bar, eliminating overlap with the dashboard's Quick Actions button.

Codebase Patterns I Verified

• Nav-bar click handlers: The existing d-flex align-items-center zone uses inline onclick handlers (onclick="showUpdateModal()", onclick="checkForUpdate()") and inline style attributes — the new <a> element matches this pattern exactly.
• feedback-btn references: Searched all .py and .html files — zero references to the old feedback-btn ID remain. Clean removal, no orphaned selectors.
• showFeedbackModal() / feedbackModal: Not present in the current develop checkout, but the diff context lines confirm they live in the PR branch's base.html (introduced by PR #158). The modal HTML is unchanged/context-only in this diff — correct, the PR only moves the trigger.
• Version bump consistency: app.py, CHANGELOG.md, and README.md all agree on 0.9.0-beta.129.

✅ Good

• Floating fixed button removed entirely, including its <style> block — no CSS leakage.
• href="#" + return false; correctly prevents page-top scroll-jump, matching expected link behavior.
• Title changed from "Send Feedback" to "Report Bug" — semantically matches the bi-bug icon swap.
• bi-bug is a Bootstrap Icons icon that already ships with the project (other BI icons used throughout).
• No changes to the feedback modal itself or any error auto-reporting code — scope is surgical.
• Docs updated correctly: CHANGELOG, README badge, and README recent-changes section all updated.

🚨 Issues Found

No issues found.

📋 Scope Verification

Issue	Problem	Addressed?	Notes
#159	Floating button conflicts with dashboard Quick Actions, inconsistent across pages	✅	Bug icon in nav, floating button fully removed, modal unchanged

Scope Status: SCOPE_OK

📝 Documentation Check

• CHANGELOG.md: ✅ Updated — correct version, accurate description
• README.md: ✅ Updated — badge and recent-changes section reflect beta.129

🎯 Verdict

APPROVE — Clean, minimal, does exactly what it says. No security, error handling, or logic concerns. The nav-bar pattern matches existing code. Ship it.