v0.8.3

## What's Changed
* docs: add v0.8.2 changelog by @qnixsynapse in https://github.com/janhq/jan/pull/8246
* merge release/v0.8.2 to main by @qnixsynapse in https://github.com/janhq/jan/pull/8250
* chore: add flatpak manifest 0.8.2 by @Minh141120 in https://github.com/janhq/jan/pull/8259
* fix: use Windows copy command in build-cli Makefile target by @ianmohney in https://github.com/janhq/jan/pull/8293
* Updated translation by @albanobattistella in https://github.com/janhq/jan/pull/8262
* fix(mcp): browser port leak and auto-disable ux by @abn in https://github.com/janhq/jan/pull/8317
* Merge dev/v0.8.3 to main by @qnixsynapse in https://github.com/janhq/jan/pull/8310
* docs: clarify Jan model quick-start flow by @archit-goyal in https://github.com/janhq/jan/pull/8323
* Fix: correct sampler defaults, fix sheet layout under window controls, and harden backend installs by @qnixsynapse in https://github.com/janhq/jan/pull/8327
* fix(csp): allow data:/blob: media so video uploads load by @qnixsynapse in https://github.com/janhq/jan/pull/8330
* fix(markdown): render lone <svg> in a code fence; don't extract <svg> nested in real code by @qnixsynapse in https://github.com/janhq/jan/pull/8332
* fix(chat): render media on first-message send by @qnixsynapse in https://github.com/janhq/jan/pull/8337

## New Contributors
* @ianmohney made their first contribution in https://github.com/janhq/jan/pull/8293
* @abn made their first contribution in https://github.com/janhq/jan/pull/8317
* @archit-goyal made their first contribution in https://github.com/janhq/jan/pull/8323

**Full Changelog**: https://github.com/janhq/jan/compare/v0.8.2...v0.8.3