Simplify web tutorials and enable all in CI

[WiktorStarczewski]

Summary

• Remove unnecessary client.sync() calls — waitFor() and execute() already sync internally, so explicit syncs after these calls were redundant
• Extract MASM code from inline template literals into separate .masm files with a webpack loader
• Simplify counter value display using Word.toU64s() instead of manual hex conversion
• Update getOrImport helpers to accept bech32 strings directly
• Update tutorials for simplified notes API (listAvailable, send, consume)
• Update send() API from authenticated: false to returnNote: true
• Enable all web tutorials in CI (previously incrementCounterContract and foreignProcedureInvocation were skipped)
• Fix empty array expansion in run_tutorials.sh for set -u compatibility

Test plan

• All 5 web tutorials pass (yarn tutorials --web)
• Previously skipped tutorials (incrementCounterContract, foreignProcedureInvocation) pass when explicitly run

[Keinberger]

Hey @WiktorStarczewski, thanks for the quick follow-up on #164! Really nice cleanup, the MASM
extraction alone is a big win IMO since that code was duplicated between the counter and FPI
tutorials. Killing the redundant syncs and enabling all tutorials in CI is great too!

I went through the full diff and it looks solid. Two small nits:

• The closing ::: for the tip admonition blocks looks like it's indented under the list item. I think it needs to be at the start of its own line (unindented) to close properly. Could you double check that it renders correctly?
• For toU64s()[3], could we add a small inline comment explaining why index 3? Something like // counter value is stored in the last felt of the word. Not blocking, just a readability thing since the magic number might trip someone up :)

LGTM, let's merge once you've verified the admonition rendering. Thanks!

[partylikeits1983]

Very nice!