fix(search): distinguish invalid QMD output

[moomooskycow]

Intent

Stop directing operators toward installation or collection recovery when QMD exits successfully but violates its JSON output contract.

Decision

Add the typed qmd.ErrInvalidOutput boundary for non-JSON and malformed JSON stdout. CLI and MCP continue to return the stable search_unavailable conflict but now use a data-specific recovery hint for producer output failures; process/dependency failures keep the installation/index hint. Integer and decimal score shapes remain native float64 decoding.

The historical deployed failure no longer reproduces with installed QMD 2.6.3: the exact September BM25 journal query now returns structured results. The malformed fixture preserves the original decimal-boundary failure shape and proves truthful handling if it recurs.

Checks

• ./scripts/check.sh: passed.
• CLI and MCP malformed-output boundary tests: passed.
• QMD integer/decimal score and malformed-output tests: passed.
• Real go run ./cmd/exocortex search September --mode bm25 --type journal: returned structured Daybook results.

Rollback

Revert this PR. Search dependency failures remain unchanged; only successful-process invalid-output diagnostics would return to the generic hint.

[coderabbitai]

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📥 Commits

Reviewing files that changed from the base of the PR and between b45e427 and 601bb7d.

📒 Files selected for processing (7)

• internal/cli/cli.go
• internal/cli/orient_test.go
• internal/mcp/mcp.go
• internal/mcp/search_test.go
• internal/qmd/qmd.go
• internal/qmd/qmd_test.go
• modules.budget

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[chatgpt-codex-connector]

Codex Review Summary

This comment shows the latest Codex review activity on this pull request.

Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-09-01T23:40:08.557890Z	601bb7d	PR opened

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[chatgpt-codex-connector]

💡 Codex Review

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Reviewed commit: 601bb7d02b

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[chatgpt-codex-connector]

Apply the invalid-output hint to brief

When exocortex brief receives malformed or non-JSON output from both the hybrid query and its BM25 fallback, qmd.Search returns ErrInvalidOutput, but cmdBrief still emits its hard-coded installation/indexing hint at internal/cli/cli.go:482. As a result, the new classification remains bypassed for the core brief operation and continues sending operators toward the wrong recovery action; route that error through FailureHint(err) as well.

AGENTS.md reference: AGENTS.md:L18-L18

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