WIP: faster markdown

[chrisnojima]

Faster markdown parsing

Changes:

1. Fast-path for plain text — 3 tiers: none/serviceOnly/full parse level. Plain text messages skip parsing entirely.
2. Plain text fast path for all modes — preview, serviceOnly, serviceOnlyNoWrap, regular rendering.
3. Lightweight service-only parser — 6 rules instead of 15 for messages with only $>kb$ decorations.
4. AST parse cache — LRU (200 entries) avoids re-parsing same text on re-render.
5. ServiceDecoration JSON cache — LRU (500 entries) for base64+JSON decode.
6. Hoisted default styleOverride — prevents new {} on every render.
7. Removed ErrorBoundary on mobile and fast paths.
8. Hoisted blockQuote regexes — moved from function body to closure.
9. Simplified serviceDecoration matcher — removed wrapper function.
10. Fast-path text regex — skip TLD matching when no .@: in source.
11. Removed lodash isArray — use native Array.isArray.
12. Removed dead noMarkdownParser code.

Results (inbox scroll, 300 small rows):

Metric	Baseline	After	Change
React total	6252ms	~5600ms	~-10%
InboxRow-small	2481ms	~2230ms	~-10%
FPS avg	52.9	~54	~+2%
FPS min	16	43+	better
FPS p5	32	46	+44%

• test thread
• i see non parsed service decorations