docs: fix premature Leiden references in backlog

The section description referenced src/graph/algorithms/leiden/ which
does not exist yet (pending PR #545). Item #96 was incorrectly marked
DONE when graphology is still a live dependency. Updated section to be
forward-looking and reverted #96 to BLOCKED on #545.

Author: carlos-alm

docs/roadmap/BACKLOG.md

@@ -114,7 +114,7 @@ Co-change data captures historical coupling from git history. Currently only use
 
 ### Tier 1e.1 — Community leverage (build on vendored Leiden algorithm)
 
-Community detection uses a vendored Leiden optimiser (`src/graph/algorithms/leiden/`) with full control over resolution, quality functions, and refinement. Currently only consumed by `communities` command and HTML viewer enrichment. These features deepen community awareness across the analysis pipeline.
+Community detection will use a vendored Leiden optimiser (PR #545) with full control over resolution, quality functions, and refinement. Currently consumed by `communities` command and HTML viewer enrichment via `graphology-communities-louvain`. These features deepen community awareness across the analysis pipeline once the Leiden vendoring lands.
 
 | ID | Title | Description | Category | Benefit | Zero-dep | Foundation-aligned | Problem-fit (1-5) | Breaking | Depends on |
 |----|-------|-------------|----------|---------|----------|-------------------|-------------------|----------|------------|
@@ -200,7 +200,7 @@ Items identified by the architectural audit (v3.1.4) that don't fit existing tie
 | 93 | ~~Shell completion for CLI~~ | ~~Commander supports shell completion but it's not implemented. `codegraph completion bash\|zsh\|fish` outputs the appropriate script. Basic UX gap for a CLI tool with 40+ commands.~~ | Developer Experience | ~~Tab completion makes the CLI discoverable — users find commands without reading docs. Reduces friction for new users and agents exploring available commands~~ | ✓ | ✓ | 2 | No | — | **PROMOTED** — Moved to ROADMAP Phase 7.11 |
 | 94 | VS Code extension | Replace the planned Web UI (removed from roadmap Phase 12) with a VS Code extension providing: webview-based graph visualization (reusing the existing `viewer.js` HTML), go-to-definition via graph edges, inline impact annotations on hover, integration with the MCP server for queries, and a sidebar panel for triage/audit results. VS Code is the right UI target for developer tools in 2026. | Visualization | Developers get graph intelligence directly in their editor — no context switching to a browser or terminal. Impact annotations on hover surface blast radius without running commands | ✗ | ✓ | 3 | No | — |
 | 95 | SARIF output for cycle detection | Add SARIF output format so cycle detection integrates with GitHub Code Scanning, showing issues inline in PRs. Currently planned for Phase 11 but could be delivered as early as Phase 7 since it's a pure output format addition. | CI | GitHub Code Scanning integration surfaces cycle violations directly in PR review — no separate CI step or comment bot needed | ✓ | ✓ | 3 | No | — |
-| 96 | ~~Fix README runtime dependency count~~ | ~~README claims "Only 3 runtime dependencies" but there are 5 — it omits `graphology` and `graphology-communities-louvain` which are in `package.json` `dependencies` (not optional). Correct to 5.~~ | Documentation | ~~Accuracy — users and contributors should be able to trust the README~~ | ✓ | ✓ | 1 | No | — | **DONE** — `graphology` and `graphology-communities-louvain` removed by vendoring Leiden algorithm. Runtime dependency count is now back to 3. |
+| 96 | Fix README runtime dependency count | README claims "Only 3 runtime dependencies" but there are 5 — it omits `graphology` and `graphology-communities-louvain` which are in `package.json` `dependencies` (not optional). Correct to 5. | Documentation | Accuracy — users and contributors should be able to trust the README | ✓ | ✓ | 1 | No | #545 | **BLOCKED** — Will be resolved when PR #545 (vendor Leiden) lands, removing `graphology` and `graphology-communities-louvain`. |
 
 ### Tier 2 — Foundation-aligned, needs dependencies