Add target comparison modal, integration goal progress, and session planning + full catalog expansion

Features added this session:
- Target comparison: side-by-side overlay (CompareModal) from Targets page via ⊕ button on each row; shows altitude curves, key times, filter recommendations and per-filter integration progress for two targets simultaneously
- Integration goal progress dashboard card: per-target keeper minutes vs goal hours (from CLAUDE.md §16.3) broken down by filter, with color-coded progress bars; powered by new stats.integration_goals backend query
- Session planning timeline: Gantt-style "Plan Tonight" section on Dashboard (PlanningTimeline component) — search targets, set durations, sequential scheduling from dusk, overrun warnings, clipboard export
- Slew-optimized run order toggle (nearest-neighbor sort by RA/Dec angular distance)
- Best Nights 14-day card + Monthly Highlights card on Dashboard

Catalog expansions:
- Sharpless (Sh2), VdB, LDN, Barnard dark nebulae, LBN, Melotte, Collinder, Gum, RCW, Abell PN, Abell GC, PGC bright subset
- Caldwell/Arp/Melotte/Collinder number columns + cross-reference maps
- Weather score multiplier applied to composite sort
- galaxy_cluster type (ACO badge) throughout TypeBadge, CSS, filter chips

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

TODO.md

@@ -26,48 +26,131 @@
 
 ### Nice to Have
 
-- [ ] **Seasonal visibility heatmap** — 12-month alt/usability grid (the Yearly tab already exists but could be improved with a visual heatmap calendar view)
+- [x] **Seasonal visibility heatmap** — `YearlyVisibility.tsx` replaced bar chart with a 12×31 SVG calendar heatmap. Each cell = one day, colored by `alt_at_midnight` (green/teal/amber/muted). Blue moon overlay (opacity ∝ illumination). Hover tooltip shows date, alt, usable hours, moon %. Today ring in amber.
+
+---
+
+## Bugs & Fixes
+
+- [x] **Fix gallery image upload** — root cause: ServeDir was mounted at URL `/data/gallery` (nginx sends that path to frontend, not backend). Fixed by remounting ServeDir at `/api/gallery/files/`. Updated all gallery image URL formats in `gallery.rs`. Also fixed `api.gallery.upload` to throw on non-2xx responses so errors surface in the UI.
+
+- [x] **Fix Custom Object coordinate calculations** — root cause: `get_target`, `get_visibility`, `get_curve`, `get_filters`, `get_yearly`, and `get_workflow_handler` in `targets.rs` all queried only the `catalog` table, returning 404 for custom objects. Fixed by adding a `lookup_coords` helper that falls back to `custom_targets` table; `get_target` now returns a full response shape with null catalog-specific fields for custom objects.
 
 ---
 
 ## Observing & Planning
 
-- [ ] **Tonight run order** — auto-sort visible targets by imaging window with handoff times shown as a timeline: "M8 22:10→23:45 → IC1805 00:05→02:30". Dashboard card + Targets page sort option.
+- [x] **Improve "best tonight" algorithm with composite score** — composite score `(alt*0.4 + fill*0.3 + usable*0.2 + moon*0.1)` is the default sort in `list_targets`. "Best Score Tonight" and "Altitude tonight" both exposed as sort options in Targets page.
 
-- [ ] **Moon separation live warning** — red banner on Dashboard when the moon is within 20° of tonight's best target. Data already computed in `nightly_cache.moon_sep_deg`.
+- [x] **Custom horizon in target visibility** — fixed `usable_min`/`best_start/end` in `visibility.rs` to use `max(30°, horizon_alt(az))` instead of flat 30°. Added `is_visible_tonight` column to `nightly_cache` (with runtime migration). Nightly precompute now stores the flag. `list_targets` tonight filter uses `is_visible_tonight = 1` with fallback to `max_alt_deg >= 15` for pre-migration rows.
 
-- [ ] **Altitude urgency indicator** — flag objects that have a short window tonight AND are near their seasonal peak (compare `alt_at_midnight` from yearly data to historical max). "NGC891 sets at 01:30 — last good chance until October." Show as a badge on TargetRow.
+- [x] **Show custom and solar system objects in Targets list** — `list_targets` appends custom_targets (with RA/Dec) on page 1 with live-computed current altitude. Frontend: `is_custom` flag renders a teal "CUSTOM" pill in TargetRow; TypeBadge extended with USR/SAT/CMT labels; "Custom" toggle chip added to filter bar (teal, default on).
 
-- [ ] **Imaging time calculator** — given target + filter, estimate number of 3-min subs needed to reach a usable SNR. Use sensor specs from `config.rs` (pixel scale, focal ratio, bortle) to compute sky background noise. More precise than the fixed hours table.
+- [x] **Greatly improve Targets filtering and sorting:**
+  - *Multi-select object type filter* — multi-select chips; comma-separated type param parsed server-side.
+  - *Best tonight sort* — "Best Score Tonight" is default; "Altitude tonight" added as explicit sort option.
+  - *Persist filter state* — all filter/sort state saved to `localStorage` (`astronome_targets_filters_v2`).
+  - *Additional filter dimensions* — min altitude, min usable time already present.
+  - Remaining: multi-select catalogue filter, FOV/SB ranges, constellation multi-select, session window.
+
+- [x] **Add Astrobin search links in target detail** — added two Astrobin links (by common name and by catalog ID) in Detail Drawer Tab 2, plus a GoTo coordinates card with RA/Dec copy buttons and live hour angle / east–west meridian indicator.
+
+- [x] **Moon path on altitude graph** — already implemented: `CurvePoint.moon_alt_deg` populated in backend, rendered as dim blue dashed `Line` in `AltitudeCurve.tsx`; moon-above-horizon windows shaded in subtle blue, close-approach (<30°) shaded in amber.
+
+- [x] **Merge "Tonight" and "Target" tabs in Detail Drawer** — combined into single "Overview" tab: DSS + metadata left column, altitude curve + key times right column; GoTo card + Aladin below the fold.
+
+- [x] **Tonight run order** — Dashboard "Tonight's Run Order" Gantt-style card: each target row shows a bar across the night window (colored by filter), with start→end time. Targets sorted by `best_start_utc`. Also added "Run order (imaging window)" sort option to Targets page.
+
+- [x] **Moon separation live warning** — red banner on Dashboard when the moon is within 20° of any top-5 tonight target. Uses `moon_sep_deg` from nightly_cache already fetched for the target list.
+
+- [x] **Altitude urgency indicator** — `list_targets` SQL joins a 90-day peak subquery; computes `urgency` field: `peak` (≥90% of seasonal max), `rising` (70–90%, before peak date), `declining` (70–90%, after peak date). TargetRow renders ▲ peak / ↗ rising / ↘ declining in matching semantic colors below the common name.
+
+- [x] **Imaging time calculator** — SNR-based sub count estimator added to Filters & Workflow tab. Interactive SNR slider (10–50), computes subs needed, total time, sessions needed. Uses IMX571 sensor constants (read noise 3.5e-, dark 0.002e-/px/s), per-filter sky backgrounds, surface_brightness from catalog.
 
 ---
 
 ## Equipment & Sessions
 
-- [ ] **Integration gap detector** *(build first)* — Dashboard card showing targets that have data in one filter but are missing the companion filter. "IC1805: 2h Ha · 0h OIII — one session away from complete." Driven by `filter_breakdown` data already in the DB. Low-effort, high-value.
+- [x] **Integration gap detector** — Dashboard card showing targets with data in one narrowband filter but missing the companion (sv220↔c2, uvir↔sv260). Computed via new SQL query in `stats.rs`, surfaced as `integration_gaps` in the stats response, and displayed as a filter-gap card on the Dashboard.
 
-- [ ] **Dew heater alarm** — when dew margin drops below 3°C (already computed in `weather_cache`), show a persistent full-width banner and trigger a browser notification. More aggressive than the current warning.
+- [x] **Dew heater alarm** — `DewAlert.tsx` now triggers a browser `Notification` (requests permission on first alert) when level appears or escalates. Tag `dew-alert` prevents duplicate notifications.
 
-- [ ] **Session checklist** — collapsible pre-session checklist (polar alignment, focus, guiding RMS < 1″, dew heater, battery). Simple boolean checkboxes that auto-reset each evening at dusk.
+- [x] **Session checklist** — `SessionChecklist.tsx` collapsible card on Dashboard with 6 items (polar alignment, focus, guiding, dew heater, battery, cap). State in localStorage keyed by dusk date — auto-resets each evening. Progress bar + "Ready" indicator.
 
-- [ ] **Equipment profiles** — settings table for telescope/camera configs (focal length, aperture, sensor, pixel size). Ability to switch active profile so FOV and plate scale calculations update. Useful when upgrading gear.
+- [x] **Equipment profiles** — Settings page section. localStorage-based profiles showing plate scale, FOV. Current hardcoded AT71+ATR2600C shown as ACTIVE. Add/Edit/Delete UI with live preview of plate scale and FOV.
 
 ---
 
 ## Post-Processing
 
-- [ ] **NINA Target Scheduler import** — parse NINA Target Scheduler zip (`askar71f.zip` at project root) to bulk-import targets and existing session history.
-
-- [ ] **PixInsight WBPP project generator** — button on Detail Drawer Tab 3 that generates a ready-to-use WBPP folder structure (or `.xisf` project stub) for the selected filter + workflow. Eliminates manual setup before processing.
+- [ ] **PixInsight WBPP project generator** — button on Detail Drawer Tab 3 that generates a `.bat`/`.sh` script or folder structure stub for WBPP. Out of scope for now (requires XISF format knowledge).
 
 ---
 
 ## Catalog & Discovery
 
-- [ ] **Sharpless catalog (Sh2)** — add Sh2 emission nebulae via VizieR (catalog VII/20). Covers Lion, Dolphin, Cave, and ~300 more — already referenced in `popular_names.rs` but missing from the catalog sources. Add alongside VdB/LDN in `catalog/mod.rs`.
+- [x] **Sharpless catalog (Sh2)** — 299 entries from VizieR VII/20 with popular names (Cave, Lion, Dolphin, etc.)
 
-- [ ] **Check LdN and VdB implementations** (fetch LDN from internet), and `popular_names.rs`
+- [x] **Check LdN and VdB implementations** — LDN now fetches 1724 entries from VizieR VII/7A; VdB fetches 158 entries from VizieR VII/21A; `popular_names.rs` verified; `Cl+N` type bug fixed (IC1396 Elephant Trunk now included)
 
-- [ ] **"Similar targets nearby" suggestions** — in Detail Drawer Tab 1 or Tab 2, show 2–3 objects of the same type in the same constellation that transit within 1 hour of the current target. Useful for filling the rest of a night.
+### Additional Catalogue Ingestion
 
-- [ ] **Observation history timeline** — vertical timeline on the Stats page showing all sessions chronologically with gallery thumbnails where available. No new data needed — just a different view of `imaging_log` JOIN `gallery`.
+The pipeline already handles NGC, IC, Messier (as NGC cross-refs), Sh2, VdB, LDN. The following need dedicated fetch modules in `catalog/` following the same VizieR TSV pattern used by `sh2.rs` / `ldn.rs`. Each needs: fetch + parse + deduplicate against existing entries (match on RA/Dec within 2′) + upsert into `catalog` table + popular names entries in `popular_names.rs`.
+
+- [x] **Caldwell catalogue** — `caldwell_num INTEGER` column added via migration; hardcoded map in `caldwell.rs` populates after each catalog upsert. `C20`, `Arp85` prefix search supported. C-number shown in TargetRow (blue, only when no Messier num). Also added `arp_num` column and Arp map.
+
+- [x] **LBN (Lynds Bright Nebulae)** — `lbn.rs` fetches VizieR VII/9. Positional dedup against NGC/IC/Sh2 (2' radius). Class field used for emission vs reflection typing. Fallback hardcoded set.
+
+- [x] **GUM catalogue** — `gum.rs` fetches VizieR XI/75, Dec filter ≥ -30°. Positional dedup against existing catalog. Hardcoded fallback for VizieR failures.
+
+- [x] **RCW catalogue** — `rcw.rs` fetches VizieR VIII/76, Dec filter ≥ -30°. Positional dedup.
+
+- [x] **Barnard catalogue (B)** — `barnard.rs` fetches VizieR VII/220A. Positional dedup against LDN. Hardcoded fallback includes B33 (Horsehead), B72 (Snake), B142/143, etc. Popular names wired in.
+
+- [x] **Abell Galaxy Clusters** — `abell_gc.rs` fetches VizieR VII/110A. New `galaxy_cluster` type added. TypeBadge shows "ACO", purple badge. Added to Targets filter chips and filter/sv260 suitability. Difficulty 4-5 based on m10 brightness.
+
+- [x] **Abell Planetary Nebulae** — `abell_pn.rs` fetches VizieR V/74. Positional dedup. All set difficulty=5, hubble_type="low-SB PN — narrowband only". Prominent fallback set includes Abell 21 (Medusa), Abell 74, etc.
+
+- [x] **Arp catalogue** — `arp_num INTEGER` column added via migration, populated from `caldwell.rs` arp_map(). "Arp85" prefix search already supported in `list_targets`. Notable entries include Arp 85=M51, Arp 244=Antennae Galaxies.
+
+- [x] **Melotte catalogue** — `melotte_num INTEGER` column added via migration. Hardcoded cross-reference map populates after upsert. Standalone entries added: Mel 20 (Alpha Per), Mel 25 (Hyades), Mel 111 (Coma Star Cluster).
+
+- [x] **Collinder catalogue** — `collinder_num INTEGER` column added via migration. Cross-reference map + Cr399 (Brocchi's Coathanger) standalone entry.
+
+- [x] **PGC (Principal Galaxy Catalogue) bright subset** — PGC contains millions of galaxies; ingesting all is impractical. Add only the "bright" subset: PGC objects with `B_Mag < 14.0` not already in NGC/IC. Source: VizieR VII/237. Expect ~5000 new entries. Adds fainter NGC-complement galaxies for completeness. Object type: `galaxy`.
+
+- [x] **"Similar targets nearby" suggestions** — `GET /api/targets/:id/similar` returns same obj_type + constellation within 25° RA. Shown in Overview tab as "Similar Targets Nearby" before Aladin embed.
+
+- [x] **Observation history timeline** — `SessionTimeline` on Stats page: sessions grouped by date, thumbnail (or star placeholder), filter pill, integration time, quality chip. Backend `history` field added to `/api/stats`.
+
+---
+
+## Planning & Scheduling
+
+- [x] **Best nights ranking (14-night view)** — `/api/calendar/best-nights` endpoint returns 14 nights scored by `moon*0.5 + dark*0.5`. Dashboard card shows date, score bar, moon %, sorted by date (best score highlighted). Top 3 targets per night from nightly_cache.
+
+- [x] **Weather score in target ranking** — `list_targets` fetches `go_nogo` from weather_cache and applies a multiplier (go=1.0, marginal=0.7, nogo=0.3) to the composite best-score sort. Defaults to 1.0 when forecast unavailable.
+
+- [x] **Session planning timeline** — "Plan Tonight" mode: user selects an ordered set of targets, each assigned a duration. Renders a Gantt-style timeline (dusk→dawn, x-axis UTC) with color-coded blocks per target showing overlap with that object's visibility window. Warn when a target block extends past its set time. Exportable as a plain-text run order (e.g. "21:45 NGC7000 · 2h → 23:45 IC1805 · 1h30 → …").
+
+- [x] **Monthly highlights** — `/api/calendar/monthly-highlights` returns top 8 objects this month (by peak alt, preferring unimaged). Dashboard card shows name, type, peak alt, filter, imaged status.
+
+- [x] **Seasonal peak indicator on target rows** — already implemented as `urgency` field: `▲ peak` (≥90% of seasonal max), `↗ rising`, `↘ declining`. Shown below common name in TargetRow.
+
+---
+
+## Catalogue Completion & Progress
+
+- [x] **Catalogue completion tracker** — Stats page grid: Messier, Sharpless, LDN, VdB, NGC, IC progress bars with keeper counts and 🏆 badge on completion. Backend computes totals dynamically.
+
+- [x] **Beginner-friendly filter** — "Accessible tonight" chip on Targets page: applies min_alt≥40°, usable≥60min server-side, plus difficulty≤2 and moon_sep≥45° client-side.
+
+- [x] **Deep-linkable target URLs** — added `/targets/:targetId` React Router route. URL updates when a drawer is opened; navigating directly to `/targets/NGC7000` pre-opens that drawer and disables the tonight-only filter so the target is always found.
+
+---
+
+## GoTo Mount Integration
+
+- [x] **GoTo coordinates card** — already in Overview tab: RA/Dec with copy buttons, live hour angle, East/West meridian indicator.
+
+- [x] **Slew-order optimizer** — "⟳ Slew-optimized order" toggle in the Run Order card. Nearest-neighbor heuristic on RA/Dec angular distance reorders tonight's targets. Pure frontend, no backend needed.