Make SSH readiness handling more idiomatic Effect

[cursor]

What Changed

• Converted SSH package errors from Data.TaggedError to serializable Schema.TaggedErrorClass definitions.
• Split SSH readiness failures into granular tagged error variants with structured metadata.
• Updated HTTP readiness timing to accept Duration.Input values and track optional last-failure state with Option.
• Replaced downstream schema-error checks with hoisted Schema.is guards.

Why

This keeps the SSH Effect code closer to the rest of the codebase's idioms: schema-backed errors are serializable and structured, timing policies flow through Duration and Effect timeout/retry primitives, and optional diagnostic state avoids null sentinels.

UI Changes

None.

Checklist

• This PR is small and focused
• I explained what changed and why
• I included before/after screenshots for any UI changes
• I included a video for animation/interaction changes

  

Note

Refactor SSH error classes to Schema.TaggedErrorClass with granular readiness error variants

• Converts all SSH error classes in packages/ssh/src/errors.ts from Data.TaggedError to Schema.TaggedErrorClass, enabling schema-based type guards (Schema.is) in place of instanceof checks.
• Splits the single SshReadinessError class into three distinct variants: SshReadinessProbeFailedError, SshReadinessProbeTimedOutError, and SshReadinessTimedOutError, each carrying specific timing and URL metadata.
• Updates waitForHttpReady in packages/ssh/src/tunnel.ts to accept Duration.Input fields instead of numeric milliseconds, and emits the new specific error variants.
• Replaces numeric millisecond timeout constants throughout tunnel.ts with Duration values; computed millisecond values are equivalent.
• Risk: All instanceof checks against the old SSH error classes will no longer match; callers must migrate to the schema-based Schema.is guards or the exported isSshReadinessError predicate.

^{Macroscope summarized 1c5a80e.}