feat(tui): copy-on-select, configurable copy key, clearer Select label

[saada]

What

Makes copying logs out of the TUI ergonomic and configurable:

1. Copy-on-select (mouse): releasing a mouse drag in selection mode copies the highlight to the clipboard automatically — no Enter needed.
2. Configurable keyboard copy key: new log_copy shortcut, default Enter (fully backward compatible), so it can be rebound — e.g. y for a Vim-style yank.
3. Clearer footer label: the selection toggle now reads Enable Select / Disable Select (the action) instead of Select On / Select Off (which read as current state).
4. Docs: new "Copying Logs to the Clipboard" section in www/docs/tui.md, including the OSC 52 fallback — previously undocumented.

# $XDG_CONFIG_HOME/process-compose/shortcuts.yaml
shortcuts:
  log_copy:
    shortcut: y   # Vim-style yank instead of Enter

Why

The copy key (Enter) and exit key (Esc) in selection mode were the only TUI bindings not covered by the configurable shortcuts system, and "turn Select on → highlight → nothing's in my clipboard until I press Enter" is a recurring point of confusion. Ctrl+C can't simply be adopted for copy because it's already the global quit binding (and forwards SIGINT to a focused interactive process), so copy-on-select plus a configurable copy key is the pragmatic fix.

How

• src/tui/actions.go — new ActionLogCopy (log_copy), default tcell.KeyCR in defaultShortcuts, and a ShortCutKeys entry. Relabels ActionLogSelection's ToggleDescription. log_copy is intentionally left out of the footer/help order arrays, so the footer layout is unchanged.
• src/tui/log-operations.go — copy logic extracted into copyLogSelection(collapse bool) (ignores empty selections so a stray click/press never clobbers the clipboard). The keyboard path matches the configured key via isLogCopyEvent (special key or rune); the title hint uses logCopyShortcut. A SetMouseCapture on the text area copies on MouseLeftUp. Esc still exits.
• src/tui/actions_test.go — unit tests for the default (Enter) and overrides (y rune, Ctrl-Y key).
• www/docs/tui.md — new docs section.

Behavior notes

• Default keyboard behavior is unchanged: Enter still copies, Esc still exits.
• Copy-on-select fires only on a deliberate mouse drag release with a non-empty selection, in selection mode. If you'd prefer it gated behind a config flag, easy to add.
• The mouse path keeps the highlight visible after copying; the keyboard path collapses it (as before).

Testing

• go build ./... — clean
• go test ./... — pass (incl. new tests)
• gofmt -l / go vet ./src/tui/ — clean

Closes #509

[sonarqubecloud]

Quality Gate passed

Issues
1 New issue
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[F1bonacc1]

Hi @saada,

Thank you for the PR!
I accept that log copy should be a configurable shortcut.
And this is exactly what this PR provides, which is great.
I think "copy on selection" to the main clipboard is unexpected and should be behind a configuration or not at all.

There are also a 2 critical issues that should be addressed.

1. nil dereference
   

   process-compose/src/tui/actions.go

   Line 236 in 1057510

   func (s *ShortCuts) setAction(actName ActionName, actionFn func()) {

   
   is not wired. Setting a custom shortcut, I reproduced it with y panics here:
   

   process-compose/src/tui/actions.go

   Line 251 in 1057510

   act.actionFn()

   
   Since actionFn is nil.

Since it was missed, it's worth adding a test to catch this before fixing.

2. ActionLogCopy is missing from the help screen
   The ActionLogCopy action should be added here:
   

   process-compose/src/tui/actions.go

   Line 105 in 1057510

   var logActionsOrder = []ActionName{

[F1bonacc1]

Keyboard selection doesn't work.
Sounds like a documentation fix, not a bug.

[F1bonacc1]

The OSC 52 fallback is documented in my other repo: https://github.com/F1bonacc1/glippy#osc-52-fallback
I wouldn't add it, especially with a Reddit link.