fix: correct AWS/IAM letter reading and voice StackOne word-by-word

[StuBehan]

Summary

Two pronunciation fixes in the dev-terms map. espeak reads a lone "A" as the article "uh", so AWS came out "uh double-you ess"; and the org name StackOne was garbled as "stac kone".

Changes

• AWS / IAM read as letters — switch the spelled-out forms to the dotted form (A.W.S., I.A.M.), which forces espeak to voice the letter name "ay" instead of the article "uh". (Spelling it AY/ay doesn't work — espeak reads that as "eye"; the dots are the trick.)
• stackone → "stack one" — added to _DEV_PRONUNCIATIONS so it's spoken word-by-word.

Testing

• pytest — dev-term assertions updated to A.W.S./I.A.M., plus a new org-name test; 192 passing. ruff check . clean.
• Phonemes confirm the fix: A.W.S. → ˈeɪ.dˈʌbəljuː.ˈɛs. ("ay double-you ess"), I.A.M. → ˈaɪ.ˈeɪ.ˈɛm. ("eye ay em"), stack one → stˈæk wˌʌn.
• End-to-end:

  $ stackvox normalize "Deploy to AWS and set up IAM for StackOne."
  Deploy to A.W.S. and set up I.A.M. for stack one.
  

Related issues

Heads-up for review: baking an org name (StackOne) into core is a deliberate exception to the speech-normalization non-goal ("no domain pronunciations in StackVox") — done on request so read-aloud tooling gets it without per-consumer wiring. The acronym fixes are generic espeak corrections and squarely in scope.