fix: last_seen_ts should use file mtime not build time (PR #22811)

[Bartok9]

Summary

This PR addresses a bug in bartokgraph.py where every node in a freshly built KnowledgeGraph received last_seen_ts = time.time() (the build timestamp). This caused the Proactive Communication Loop to filter out all nodes as "recently active" (within last 24h), surfacing zero connections.

Root cause: add_node() and GraphNode defaulted to current time instead of the source file's actual modification time.

Detailed Changes

1. walk_files(directory) (hermes_cli/bartokgraph.py)

• Updated to yield (file_path, mtime) tuples.
• Uses entry.stat().st_mtime (single stat call for efficiency).
• Return type: Iterator[Tuple[str, float]]

2. build_graph(workspace_path, ...)

• Changed loop to for file_path, file_mtime in walk_files(...)
• Passes file_mtime to:
  • extract_knowledge(...)
  • extract_code(...)
  • extract_html(...)
  • _extract_json(...)
  • Direct graph.add_node(..., last_seen_ts=file_mtime) calls (for code comments, PDF, etc.)

3. Extractor Functions

• extract_knowledge(content, source, graph, weight=1.0, file_mtime=None)
• extract_code(content, file_path, source, graph, file_mtime=None)
• extract_html(content, file_path, source, graph, weight=1.0, file_mtime=None)
• _extract_json(content, source, graph, weight, file_mtime=None) (new param)
• All add_node calls inside now include last_seen_ts=file_mtime
• Inner calls (e.g. extract_knowledge from extract_html) forward the file_mtime

4. KnowledgeGraph.add_node(...)

• New optional param: last_seen_ts: Optional[float] = None
• When updating existing node: node.last_seen_ts = last_seen_ts if last_seen_ts is not None else time.time()
• When creating new node: same logic for GraphNode(..., last_seen_ts=...)
• Falls back to time.time() only for manually-added nodes (tests, incremental updates, etc.)

5. GraphNode dataclass

• last_seen_ts: float = 0.0 (was field(default_factory=time.time))
• Nodes with unknown age now correctly treated as old (enables proper temporal decay scoring in _temporal_decay)

6. New Tests (tests/test_proactive_graph.py)

def test_build_graph_last_seen_ts_matches_file_mtime():
    """Verify last_seen_ts comes from file mtime, not build time."""
    with tempfile.TemporaryDirectory() as tmpdir:
        fpath = os.path.join(tmpdir, "recent.md")
        with open(fpath, "w") as f:
            f.write("# Recent Concept\n\nThis should have correct mtime.")
        mtime = time.time() - 30 * 86400  # 30 days ago
        os.utime(fpath, (mtime, mtime))

        graph = build_graph(tmpdir, layer="knowledge")
        node = graph.nodes.get("recent-concept")
        assert node is not None
        assert abs(node.last_seen_ts - mtime) < 2.0
        assert node.last_seen_ts < time.time() - 60  # not build time


def test_build_graph_last_seen_ts_30_days_old():
    """last_seen_ts for 30-day-old file is ~30d ago (within seconds), not recent."""
    with tempfile.TemporaryDirectory() as tmpdir:
        fpath = os.path.join(tmpdir, "old.md")
        with open(fpath, "w") as f:
            f.write("# Old Concept\n\nKnowledge from the past.")
        thirty_days_ago = time.time() - 30 * 86400
        os.utime(fpath, (thirty_days_ago, thirty_days_ago))

        graph = build_graph(tmpdir, layer="knowledge")
        node = graph.nodes.get("old-concept")
        assert node is not None
        days_ago = (time.time() - node.last_seen_ts) / 86400
        assert 29.9 < days_ago < 30.1
        assert node.last_seen_ts < time.time() - 60

Impact on Proactive Communication Loop

• BartokGraphAdapter._find_connections() uses n.last_seen_ts < cutoff_ts (cutoff = now - exclude_recent_hours*3600)
• With correct mtimes, historical files (e.g. 30+ days old) now correctly appear as dormant and get scored with temporal decay boost.
• Freshly built graphs no longer incorrectly mark everything as "active now".

Testing

• All pre-existing tests continue to pass.
• New tests specifically validate mtime fidelity and age calculation.
• No changes to non-file-backed nodes (they still get time.time()).

Backward Compatibility

• Fully backward compatible. Existing graphs loaded via KnowledgeGraph.load() already used last_seen_ts from JSON (default 0.0).

This PR includes the complete implementation, tests, and rationale so the review agent can fully evaluate the fix without needing external context.

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Note

High Risk
High risk because it rewires the Docker publish workflow (multi-runner digest/manifest merge + concurrency), changes agent message conversion/compression around multimodal/tool results, and alters cron delivery/runtime behavior; regressions could break releases or message delivery across platforms.

Overview
CI/CD: Adds a reusable hermes-smoke-test composite action and updates docker-publish.yml to build amd64/arm64 on native runners, smoke-test both, push per-arch images by digest, then merge them into a tagged multi-arch manifest; concurrency is changed so PR runs cancel in-progress while main/release runs don’t, and move-latest now depends on the manifest merge.

Quality gates: Makes linting partially blocking by adding a dedicated ruff check . enforcement job plus a new blocking windows-footguns checker, and adds a new blocking uv lock --check workflow to keep uv.lock in sync with pyproject.toml.

Runtime/build: Refactors the Dockerfile to cache Python dependency install by copying only pyproject.toml/uv.lock before source, then installs the project editable without deps; docker/entrypoint.sh can now bootstrap auth.json from HERMES_AUTH_JSON_BOOTSTRAP on first run.

Agent behavior: Improves Anthropic conversion for multimodal tool results (including computer_use screenshots), adds eviction of older screenshot blocks, updates token estimation/compression to treat images as fixed-cost tokens and strip/placeholder old image payloads, and adds provider-header fallbacks from provider profiles.

Cross-platform/CLI & cron: Broad Windows hardening (UTF-8 stdio bootstrap, explicit file encodings, bash discovery for .sh cron scripts, safer worktree symlink fallback, and terminal keybinding/signal handling tweaks), adds confirmation prompts for destructive slash commands, normalizes cron job records and cleans up job output dirs on delete, adds deliver=all routing intent for cron, and introduces the MSGRAPH_WEBHOOK platform plus plugin support for standalone out-of-process sending.

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