fix: provider output handling and watch rebuild re-invocation

[glours]

What I did
Provider info and error messages containing newlines broke the TTY progress display (timer drifting to a new line, broken cursor movement). Extract only the first line for progress events via firstLine(). Full messages remain available through the provider's own debug message type.

Skip provider services during watch rebuild convergence by adding a SkipProviders flag to CreateOptions, set only by the watch rebuild path. This prevents unnecessary re-invocation of providers on every file change while preserving normal provider execution for all other commands (up, create, run, scale).

Related issue
N/A

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[Copilot]

Pull request overview

This PR improves watch-mode stability and reduces unnecessary work by (1) sanitizing provider progress messages that contain newlines (which break TTY progress rendering) and (2) avoiding repeated provider re-invocation during watch-triggered rebuild convergence.

Changes:

• Truncate provider info/error progress events to the first line via firstLine() to keep TTY progress rendering stable.
• Add SkipProviders to api.CreateOptions and use it from the watch rebuild path to prevent provider services from re-running on each file change.
• Implement provider skipping in convergence when SkipProviders is enabled.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 2 comments.

File	Description
pkg/compose/watch.go	Sets SkipProviders: true when recreating services during watch rebuilds.
pkg/compose/plugins.go	Uses firstLine() for provider progress events and adds the firstLine helper.
pkg/compose/convergence.go	Skips provider services during convergence when options.SkipProviders is set.
pkg/api/api.go	Extends CreateOptions with a SkipProviders flag.

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[Copilot]

firstLine only trims \n, so CRLF messages ("\r\n") will leave a trailing \r in the returned first line. That can still interfere with TTY cursor control and makes the doc comment (“stripping any trailing newlines”) inaccurate on Windows. Consider trimming "\r\n" and/or explicitly stripping a trailing \r from the first line segment.

Suggested change

	s = strings.TrimRight(s, "\n")
	if i := strings.IndexByte(s, '\n'); i >= 0 {
	return s[:i]
	s = strings.TrimRight(s, "\r\n")
	if i := strings.IndexByte(s, '\n'); i >= 0 {
	return strings.TrimRight(s[:i], "\r")

[Copilot]

New SkipProviders behavior is introduced here, but there doesn’t appear to be any test exercising convergence when provider services are present and SkipProviders is true. Given how central convergence is, adding a unit test that asserts provider services are not invoked (and dependent services still converge) would help prevent regressions.