Feat/auth provider proposal

[guillermomachado]

What does this do?

Propose a AuthProvider to handle tokens and authenticated flags in the app.

Why did you do this?

This way we don't need to stick with zustand just to store and expose auth tokens.

[github-actions]

💯 Test Coverage

Lines	Statements	Branches	Functions
	52.71% (340/645)	43.91% (119/271)	38.35% (84/219)

😎 Tests Results

Tests	Skipped	Failures	Errors	Time
75	0 💤	0 ❌	0 🔥	30.801s ⏱️

👀 Tests Details • (53%)

File	% Stmts	% Branch	% Funcs	% Lines	Uncovered Line #s
All files	52.71	43.91	38.35	53.22
api	0	100	0	0
types.ts	0	0	0	0
api/auth	0	100	0	0
use-user.tsx	0	100	0	0	13–21
app	0	0	0	0
_layout.tsx	0	0	0	0	21–78
app/(app)	0	0	0	0
_layout.tsx	0	0	0	0	14–64
settings.tsx	0	0	0	0	18–24
components/providers	69.33	38.88	62.5	68.91
auth.tsx	69.33	38.88	62.5	68.91	59–74, 80–96, 130, 148, 152–158, 182
components/settings	0	0	0	0
items-container.tsx	0	0	0	0	11–12
core	53.12	0	35.71	60.71
test-utils.tsx	90.9	100	80	100