fix(server): fetch content variants in get_content and list_content (COD-375)

[shivros]

Summary

Fixes COD-375

SqliteStorage::get_content() was hardcoding variants: vec![], so platform variants saved via add_variant() were never read back. This PR:

1. get_content() — Added fetch_variants_for() helper that queries the content_variants table and deserializes rows into Vec<PlatformVariant>. Variants are ordered by formatted_at ASC for deterministic retrieval.

2. list_content() — Added a correlated subquery (COUNT(*) from content_variants) and a new variant_count: usize field on ContentSummary so list views can show how many variants each content item has.

3. Error handling — Parse failures on metadata JSON or formatted_at timestamps now propagate as anyhow::Result errors with context, rather than being silently masked. Corrupt DB data surfaces as an error, not silently swallowed.

Test

New test test_get_content_returns_variants:

• Saves content, adds two variants (Twitter + LinkedIn)
• Verifies get_content() returns both variants with correct platform, text, and metadata
• Verifies ordering matches ORDER BY formatted_at ASC
• Verifies list_content() reports correct variant_count
• Verifies the no-variants edge case returns an empty vec

All 6 tests pass. cargo clippy --all-targets --all-features -- -D warnings clean. cargo fmt --check clean.

Review Notes

• Platform::from_db_key() is infallible (returns Platform, not Result) — it always maps any string to either a known variant or Other(String). This is by design from PR fix(server): fix SQLite enum serialization causing failing test_schedule_lifecycle #1.
• ContentSummary has a single construction site (list_content()), updated in this diff.

[shivros]

🤖 Automated Review Panel

Review ran against the parent session model (model override unavailable in this run). A second reviewer was not dispatched. Findings from the single review below were addressed before PR opening.

Review Findings (glm-5.1)

Verdict: Change achieves the core goal. Three issues raised:

1. 🔴 FIXED — unwrap_or_default() / unwrap_or_else(|_| Utc::now()) in fetch_variants_for masked corrupt DB data silently. Convention violation ("no silent error masking"). Fixed: now propagates via ? with anyhow context. Parse failures on metadata JSON or formatted_at timestamps surface as real errors.

2. ✅ Non-issue — Platform::from_db_key() signature. Reviewer suspected it returns Result/Option. Verified: returns Platform directly (infallible). Always maps any string to a known variant or Other(String). No change needed.

3. ✅ Non-issue — ContentSummary.variant_count breaking change. Only one construction site exists (list_content), updated in this diff.

4. ✅ Non-issue — borrow lifetime concern. rows from stmt.query() is alive when fetch_variants_for(&conn) is called. Compiled clean — rusqlite's prepare takes &self, so shared borrows coexist.

Post-review action: Error handling in fetch_variants_for rewritten to propagate all parse errors instead of silently masking them. All tests still pass.

[shivros]

Auto-Merge Gate Approval

Confidence: 0.92
Ticket: COD-375 — Fix variant retrieval in get_content storage method

Rationale

The diff directly fulfills the stated goal: SqliteStorage::get_content() was hardcoding variants: vec![], and this PR adds a fetch_variants_for() helper that queries content_variants and deserializes rows into Vec<PlatformVariant>. list_content() gains a correlated variant_count subquery. A comprehensive test (test_get_content_returns_variants) covers multi-variant retrieval, ordering, no-variant edge case, and list-count accuracy.

Acceptance Criteria (all met)

• get_content() returns all saved variants
• New test test_get_content_returns_variants passes
• cargo clippy --all-targets --all-features -- -D warnings clean (Clippy check green)
• cargo fmt --check clean (Formatting check green)
• cargo test all green (Tests check green)

Checks Observed (5/5 SUCCESS)

Check	Status
Formatting	✅
Clippy	✅
Tests	✅
Build	✅
Secret Scanning	✅

Scope Limits

• 1 file changed (crates/postghost-server/src/storage.rs), +130/-5
• No secrets, no deployment, no destructive ops, no schema migration
• Review-panel finding (silent error masking via unwrap_or_default) was addressed before PR open — errors now propagate with anyhow context

Merge Method

Squash + delete branch.

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Approved by CodeFold Auto-Merge Gate (cron ceb0befd1f30)