Stability fixes

[marta-lokhova]

• Properly spin up watchers when in pregenerated txs mode
• Upgrades: harden network limit calculation by including target block time in the calculation
• Fix SAC txSize estimate for network limits
• Fix broken support for simulate apply config flags
• Bump init delay timer. Previously, the lower limit would cause some containers to get killed sporadically on startup

[Copilot]

Pull request overview

This PR improves stability for supercluster test missions by making initialization work correctly in simulate/pregenerated transaction modes, tuning startup liveness timing, and recalculating network limits based on target block time.

Changes:

• Re-enables stellar-core init commands during simulate-apply runs while keeping simulate-apply sleep settings out of init configs.
• Adds pregenerated transaction watcher setup for non-loadgen nodes.
• Reworks min-block-time network limit sizing to account for target close time and adjusts SAC transaction size estimates.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated no comments.

File	Description
src/FSLibrary/StellarKubeSpecs.fs	Increases liveness initial delay and allows init commands to run in simulate-apply mode.
src/FSLibrary/StellarCoreCfg.fs	Splits simulate-apply config behavior between init and main containers and adds trigger timer config.
src/FSLibrary/MinBlockTimeTest.fs	Updates pregenerated tx setup and target-time-based classic/Soroban limit calculations.
src/FSLibrary/MaxTPSTest.fs	Ensures non-loadgen nodes also run pregenerated tx initialization with zero txs.

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