fix(composer): paths such as /tmp/build.sh no longer open the slash menu

[NikitaMGrimm]

Problem

Since #19107, a / at the start of any word opens the slash menu. A path is a word that starts with /, so typing Run /tmp/build.sh or /etc/hosts pops up an empty "No matching command." menu over the composer.

Change

A slash word that contains a second slash is a path, so it no longer opens the menu. The whole word counts, so a caret placed before the second slash (/et|c/hosts) is treated the same. The check is one shared helper, used by web's detectComposerTrigger and by the shared detector that mobile uses. Mobile's line-leading /model openai/gpt picker still works.

Split out of #19168, which was closed for bundling independent fixes. This PR fixes only the path popup.

Scope and approval

A small, focused fix for an obvious bug in the word-start menu added by #19107. Keeping /tmp/build.sh and /etc/hosts out of the slash menu was part of the maintainer-account direction on #8069 for inline slash commands, disclosed as agent-written on Theo's behalf.

Verification

• vp test run apps/web/src/composer-logic.test.ts packages/shared/src/composerTrigger.test.ts apps/mobile/src/features/threads/use-composer-command-menu.test.ts: 133 passed. With main's two detectors restored, the six new path cases fail (three each in web and shared).
• tsc --noEmit passes in apps/web, packages/shared and apps/mobile. Targeted lint and formatting pass.
• T3 Browser panel against an isolated dev server, main at 40a7908df5 versus this branch. Run /tmp/build.sh opens the empty menu on main and nothing here. Use /retr still offers the Retro skill.
• Not run: native mobile, or an Electron shell pass.

Note

🤖 Agent assistance: Claude Opus 5.5 via Claude Code in T3 Code

[macroscopeapp]

Approvability

Verdict: Approved at b99dd76

Macroscope's review found this PR approvable — This is a narrowly scoped composer bug fix that suppresses false slash-menu activation for path-like words while preserving normal slash commands and model selection. The shared logic is covered by focused web and mobile-facing tests, with no broader configuration, schema, or infrastructure impact.

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[coderabbitai]

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📥 Commits

Reviewing files that changed from the base of the PR and between b99dd76 and afc483a.

📒 Files selected for processing: 1

• packages/shared/src/composerTrigger.ts

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📝 Walkthrough

Slash-command detection now excludes slash-prefixed words that contain another slash before the next whitespace boundary. Tests cover filesystem paths in shared and web composer detection, and confirm that model-picker queries still trigger correctly.

Changes: Composer trigger detection

Layer / File(s)	Summary
Shared path-aware trigger detection packages/shared/src/composerTrigger.ts, packages/shared/src/composerTrigger.test.ts	The shared detector identifies path-like words and excludes them from slash-command triggers. Tests cover filesystem paths and verify that a model-picker query remains a slash-model trigger.
Web composer integration apps/web/src/composer-logic.ts, apps/web/src/composer-logic.test.ts	The web composer applies the path check. Tests cover paths at the start of text and within prose.

Priority: ⬇️ Low

Estimated code review effort: 2 (Simple) | ~10 minutes

Change: Bug fix

Suggested reviewers: juliusmarminge

Merge Risk: ⚪ Minimal · up to afc48

The change prevents filesystem paths from opening slash menus while preserving the tested command and model-picker behavior. No actionable merge-blocking risk is evident, so the PR is ready for normal checks.

### Architecture Summary

Architecture risk: 🟡 Medium · up to afc48

The change affects 2 systems.

Changed systems: packages/shared, apps/web

Architecture concerns
No architecture-level concerns identified.

Review details

Systems and components

• observed — packages/shared (library) was modified; 2 changed files map to changed impact.
• observed — apps/web (ui) was modified; 2 changed files map to changed impact.

Before / after behavior

• observed — Modified behavior in apps/web/src/composer-logic.test.ts: Added cases asserting that absolute paths are not detected as slash-command triggers, including a path embedded in prose with the cursor partway through it.
• observed — Modified behavior in apps/web/src/composer-logic.ts: Imports isPathWord for composer trigger classification.
• observed — Modified behavior in apps/web/src/composer-logic.ts: When a slash-prefixed token is a path word, detectComposerTrigger now returns null instead of classifying it as a slash command.
• observed — Modified behavior in packages/shared/src/composerTrigger.test.ts: Added cases asserting that filesystem paths are not treated as slash-menu triggers, including a path at the cursor, a standalone path, and a path following text.

Reliability and maintainability

• inferred — Risk-relevant change factors for packages/shared: blast_radius_1; direct_dependents_1

Pre-merge checks: 4

Check name	Status	Explanation
Title check		The title clearly and concisely describes the main fix: filesystem paths such as /tmp/build.sh no longer open the slash menu.
Description check		The description covers the problem, expected behavior, implementation, scope and approval context, verification results, limitations, visual evidence, and agent assistance. It is complete and aligned …
Linked Issues check		Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check		Check skipped because no linked issues were found for this pull request.

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