Add token auth persistence and fix Linux HTML stats rendering

[SpiritGun91]

Overview

This PR improves reliability, usability, and Linux compatibility for GitHub user data extraction and HTML report viewing.

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Highlights

• Added authenticated GitHub API support via personal access token.
• Persisted token across runs using a local token file.
• Fixed Linux HTML viewer path so the generated report opens correctly.
• Suppressed noisy dconf and MESA startup warnings in Linux viewer flow.
• Fixed broken stats images by embedding fetched images as base64 data URIs.
• Replaced paused stats endpoints with working alternatives.

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What Changed

Authentication and Rate Limits

• Added authenticated request headers when GITHUB_TOKEN is present.
• Kept graceful fallback behavior when no token is provided.

Token Persistence

• Added token load and save flow in startup prompt logic.
• Added local token file to git ignore rules to avoid accidental secret commits.

Linux Viewer Reliability

• Updated Linux viewer to open the generated index.html through an absolute path.
• Added Linux environment defaults to reduce terminal warning noise.

Stats Rendering Fixes

• Added fetch + base64 data URI fallback for stats images.
• Switched Top Languages and GitHub Stats providers to github-profile-summary-cards endpoints.

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Why These Changes

• Unauthenticated GitHub API usage quickly hits strict rate limits.
• Re-entering a token every run is inconvenient.
• Linux viewer had path and startup noise issues.
• External image URLs can fail under local file rendering; data URIs improve consistency.
• Previous stats provider endpoint was paused and caused broken image sections.

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Validation

• Ran the application successfully on Linux.
• Confirmed token is loaded from saved file on subsequent runs.
• Confirmed HTML report generation and viewer launch flow.
• Confirmed Top Languages, GitHub Stats, and Streak sections render correctly in the local viewer.

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Notes

• Existing unauthenticated behavior is preserved if no token is provided.
• Token file remains local and untracked by git.

[codacy-production]

Up to standards ✅

🟢 Issues 0 issues

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🟢 Metrics 15 complexity · 0 duplication

Metric	Results
Complexity	15
Duplication	0

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