feat: Update web ThemeProvider to only inject CSS Variables that are different than the parent theme

[codynova]

What changed? Why?

• Update web ThemeProvider to only inject CSS Variables that are different than the parent theme
• Add forceInjectThemeCss prop to force injecting CSS Variables, and enable it in Portal's ThemeProvider
• Update deprecation comments / warnings

Root cause (required for bugfixes)

UI changes

iOS Old	iOS New
old screenshot	new screenshot

Android Old	Android New
old screenshot	new screenshot

Web Old	Web New
old screenshot	new screenshot

Testing

How has it been tested?

• Unit tests
• Interaction tests
• Pseudo State tests
• Manual - Web
• Manual - Android (Emulator / Device)
• Manual - iOS (Emulator / Device)

Testing instructions

Change management

type=routine
risk=low
impact=sev5

automerge=false

[cb-heimdall]

🟡 Heimdall Review Status

Requirement	Status	More Info
Reviews	🟡 0/1	Denominator calculation Show calculation 1 if user is bot 0 1 if user is external 0 2 if repo is sensitive 0 From .codeflow.yml 1 Additional review requirements Show calculation Max 0 0 From CODEOWNERS 1 Global minimum 0 Max 1 1 1 if commit is unverified 0 Sum 1
CODEOWNERS	✅ None for this change

[cb-ekuersch]

closing PR will open a new one against the v9 branch