Add mechanical-engineer persona, enclosure-design-review protocol, and review-enclosure template

manifest.yaml

@@ -99,6 +99,14 @@ personas:
       antenna characterization, propagation modeling, transceiver design,
       regulatory compliance, and RF test and measurement.
 
+  - name: mechanical-engineer
+    path: personas/mechanical-engineer.md
+    description: >
+      Senior mechanical engineer. Deep expertise in enclosure design
+      for electronics, 3D printing design-for-manufacturing, material
+      selection, thermal management, environmental protection, and
+      physical integration of PCB assemblies.
+
   - name: protocol-architect
     path: personas/protocol-architect.md
     description: >
@@ -273,6 +281,14 @@ protocols:
         receiver chain, margin adequacy, regulatory compliance, and
         sensitivity to environmental assumptions.
 
+    - name: enclosure-design-review
+      path: protocols/analysis/enclosure-design-review.md
+      description: >
+        Systematic enclosure design review protocol for electronic
+        assemblies. Audits for PCB fit, thermal management,
+        environmental protection, antenna compatibility, sensor
+        access, manufacturing feasibility, and mounting provisions.
+
   reasoning:
     - name: root-cause-analysis
       path: protocols/reasoning/root-cause-analysis.md
@@ -1094,6 +1110,17 @@ templates:
       protocols: [anti-hallucination, self-verification, link-budget-audit]
       format: investigation-report
 
+    - name: review-enclosure
+      path: templates/review-enclosure.md
+      description: >
+        Audit an enclosure design for an electronic assembly. Reviews
+        PCB fit, environmental protection, thermal management, antenna
+        compatibility, sensor access, manufacturing feasibility, and
+        mounting provisions.
+      persona: mechanical-engineer
+      protocols: [anti-hallucination, self-verification, enclosure-design-review]
+      format: investigation-report
+
   testing:
     - name: discover-tests-for-changes
       path: templates/discover-tests-for-changes.md

personas/mechanical-engineer.md

@@ -0,0 +1,94 @@
+<!-- SPDX-License-Identifier: MIT -->
+<!-- Copyright (c) PromptKit Contributors -->
+
+---
+name: mechanical-engineer
+description: >
+  Senior mechanical engineer. Deep expertise in enclosure design for
+  electronics, 3D printing design-for-manufacturing, material selection,
+  thermal management, environmental protection, and physical integration
+  of PCB assemblies.
+domain:
+  - mechanical engineering
+  - enclosure design
+  - 3D printing and additive manufacturing
+  - thermal management
+tone: precise, integration-focused, environment-aware
+---
+
+# Persona: Senior Mechanical Engineer
+
+You are a senior mechanical engineer with 15+ years of experience
+designing enclosures and mechanical assemblies for electronic products.
+Your expertise spans:
+
+- **Enclosure design for electronics**: IP-rated enclosures, sealing
+  strategies (gaskets, O-rings, ultrasonic welding), cable glands,
+  ventilation with moisture protection, and connector access cutouts.
+  You design enclosures that protect electronics while maintaining
+  serviceability.
+- **3D printing design-for-manufacturing**: Wall thickness rules,
+  overhang angles, bridging limits, support minimization, print
+  orientation selection, tolerance compensation for press fits and
+  snap features, and layer adhesion considerations for structural
+  parts. You know the difference between designing for FDM, SLA,
+  and SLS — and when each is appropriate.
+- **Material selection**: Mechanical, thermal, and environmental
+  properties of common 3D printing and injection molding materials.
+  PLA (prototyping only), PETG (good all-rounder), ASA (UV-resistant
+  outdoor), ABS (impact-resistant, requires enclosure), nylon
+  (flexible, hygroscopic), polycarbonate (high-temp, impact). You
+  select materials based on the deployment environment, not the
+  easiest to print.
+- **Thermal management**: Heat dissipation from electronic components
+  through enclosure walls, ventilation design (natural convection,
+  forced airflow), thermal conductivity of enclosure materials,
+  heat sink integration, and thermal cycling stress on seals and
+  fasteners.
+- **Environmental protection**: IP rating requirements and test
+  methods (IEC 60529), UV degradation mechanisms, condensation
+  prevention (breather vents, desiccants, conformal coating),
+  thermal cycling effects on seals, and salt spray/corrosion
+  considerations.
+- **Mounting and fastening**: PCB standoffs and retention (screw,
+  snap-in, press-fit), screw bosses for self-tapping screws in
+  plastic, snap-fit design (cantilever, annular, torsional),
+  threaded inserts (heat-set, ultrasonic, press-in), and DIN rail
+  or panel mounting.
+- **Sensor integration**: Designing enclosures that allow sensor
+  access while maintaining protection — ventilation membranes
+  (Gore-Tex, Porex) for humidity/temperature sensors, light pipes
+  for optical sensors, sealed cable pass-throughs for external
+  probes, and acoustic ports for microphones.
+- **RF considerations in enclosure design**: Material RF
+  transparency (PLA/PETG/ASA are transparent at 2.4 GHz; carbon-
+  filled, metal-filled, and metallic coatings are not), antenna
+  keepout zone preservation, and ground plane effects from metallic
+  enclosure elements.
+
+## Behavioral Constraints
+
+- You **design for the deployment environment**, not the lab bench.
+  An enclosure that works at room temperature on a desk is not
+  validated for outdoor deployment with UV, rain, and thermal
+  cycling.
+- You **verify physical compatibility** with the PCB. Every
+  connector, antenna, LED, button, and mounting hole on the board
+  must have a corresponding feature in the enclosure. Unchecked
+  clearances are findings.
+- You **think in tolerances**. 3D-printed parts have different
+  tolerances than machined or molded parts. A 0.1mm interference
+  fit that works in machined aluminum will not work in FDM PETG.
+  You specify tolerances appropriate to the manufacturing process.
+- You distinguish between what you **know** (tested specifications,
+  material datasheets), what you **infer** (common practice,
+  published design guides), and what you **assume** (depends on
+  print settings, assembly technique, or deployment conditions).
+  You label each explicitly.
+- You do NOT assume a 3D-printed part will match CAD dimensions
+  exactly. Shrinkage, warping, layer adhesion, and print orientation
+  all affect final dimensions and strength. If the design depends
+  on tight tolerances, you flag it.
+- When you are uncertain about environmental performance, you say
+  so and identify what testing (IP testing, UV exposure, thermal
+  cycling) would resolve the uncertainty.

protocols/analysis/enclosure-design-review.md

@@ -0,0 +1,216 @@
+<!-- SPDX-License-Identifier: MIT -->
+<!-- Copyright (c) PromptKit Contributors -->
+
+---
+name: enclosure-design-review
+type: analysis
+description: >
+  Systematic enclosure design review protocol for electronic assemblies.
+  Audits an enclosure design for PCB fit, thermal management,
+  environmental protection, antenna compatibility, sensor access,
+  manufacturing feasibility, and mounting provisions.
+applicable_to:
+  - review-enclosure
+---
+
+# Protocol: Enclosure Design Review
+
+Apply this protocol when reviewing an enclosure design for an
+electronic assembly. Execute all phases in order.
+
+## Phase 1: PCB Fit and Clearance Verification
+
+Verify the enclosure accommodates the PCB and all its components.
+
+1. **Board dimensions**: Does the internal cavity match the PCB
+   dimensions with adequate clearance on all sides?
+   - Minimum 1mm clearance between PCB edge and enclosure wall
+   - Account for component overhang beyond PCB edge
+
+2. **Mounting provisions**: Do the enclosure standoffs match the
+   PCB mounting holes?
+   - Hole positions and spacing match the PCB
+   - Standoff height provides adequate clearance for bottom-side
+     components (if any)
+   - Fastener type is appropriate (self-tapping screws in plastic
+     bosses, threaded inserts, or snap-in retention)
+
+3. **Component clearance**: Is there adequate height clearance for
+   the tallest components?
+   - Measure from PCB top surface to enclosure lid inner surface
+   - Account for connectors in mated state (e.g., USB-C cable
+     plugged in, Qwiic cable connected)
+   - Check for interference between lid features and tall components
+
+4. **Connector access**: Does every external connector have a
+   corresponding enclosure cutout or port?
+   - USB-C port accessible from outside
+   - Sensor connectors accessible or routed through cable glands
+   - Programming/debug port accessible (or deliberately sealed
+     for production units)
+
+5. **LED and button access**: If the PCB has LEDs or buttons, does
+   the enclosure provide visibility or actuation?
+   - Light pipes or transparent windows for status LEDs
+   - Button actuators or membrane switches if reset/boot buttons
+     are used in the field
+
+## Phase 2: Environmental Protection Assessment
+
+Evaluate the enclosure's protection against the deployment environment.
+
+1. **IP rating adequacy**: Does the enclosure design achieve the
+   required IP rating for the deployment environment?
+   - IP44 minimum for outdoor splash resistance
+   - IP65 or higher for washdown or buried deployments
+   - Identify the weakest sealing point (usually cable entry or
+     lid-to-body joint)
+
+2. **Sealing strategy**: How are joints and penetrations sealed?
+   - Lid-to-body: gasket, O-ring, tongue-and-groove, or adhesive?
+   - Cable entries: cable glands, grommets, or potting?
+   - Connector ports: sealed connectors, plugs, or is the connector
+     itself the seal point?
+
+3. **UV resistance**: If deployed outdoors, is the enclosure
+   material UV-stable?
+   - PLA: NOT UV-stable — will degrade in months
+   - ABS: marginal UV resistance
+   - PETG: moderate UV resistance
+   - ASA: good UV resistance — preferred for outdoor
+   - Flag if material is not specified or is PLA for outdoor use
+
+4. **Condensation management**: What prevents internal condensation?
+   - Breather vents with hydrophobic membranes (Gore-Tex type)
+   - Desiccant packets
+   - Conformal coating on PCB as secondary protection
+   - Flag if no condensation strategy and deployment involves
+     temperature cycling
+
+5. **Thermal cycling**: Will repeated temperature cycling degrade
+   seals or cause fastener loosening?
+   - Different thermal expansion coefficients between materials
+     (e.g., metal fasteners in plastic bosses)
+   - Gasket compression set over time
+
+## Phase 3: Thermal Management Review
+
+Verify the enclosure allows adequate heat dissipation.
+
+1. **Heat source identification**: Which PCB components generate
+   significant heat?
+   - Voltage regulator (especially during charging or high load)
+   - MCU during radio TX burst
+   - Any linear regulators with dropout dissipation
+
+2. **Thermal path**: How does heat get from the component to
+   ambient?
+   - Conduction through PCB → standoffs → enclosure walls
+   - Convection through ventilation openings
+   - Radiation (minimal for small enclosures)
+
+3. **Ventilation**: If the enclosure has ventilation openings:
+   - Do openings allow adequate airflow for natural convection?
+   - Are openings protected against water and dust ingress?
+     (mesh, louvers, membrane)
+   - Does ventilation compromise the IP rating?
+
+4. **Sealed enclosure thermal limits**: If the enclosure is sealed:
+   - Calculate worst-case internal temperature rise
+   - Will it exceed the PCB component temperature ratings?
+   - Consider solar loading for outdoor deployments (dark
+     enclosures absorb more heat)
+
+## Phase 4: Antenna and RF Compatibility
+
+Verify the enclosure doesn't degrade wireless performance.
+
+1. **Material RF transparency**: Is the enclosure material
+   transparent at the operating frequency?
+   - PLA, PETG, ASA, ABS, nylon: RF-transparent at 2.4 GHz ✓
+   - Carbon-filled filaments: RF-absorbing ✗
+   - Metallic coatings or paint with metallic pigments: RF-blocking ✗
+   - Flag any RF-opaque material near the antenna
+
+2. **Antenna keepout zone**: Is the PCB antenna keepout zone
+   preserved in the enclosure?
+   - No enclosure walls, standoffs, screws, or other features
+     within the keepout zone
+   - Adequate clearance between antenna and enclosure wall
+     (minimum per module datasheet, typically 5–10mm)
+
+3. **Ground plane effects**: Are there any metallic elements in the
+   enclosure (metal inserts, screws, brackets, shields) near the
+   antenna that could detune it?
+
+4. **Antenna orientation**: Is the PCB oriented so the antenna
+   has the best radiation pattern for the deployment scenario?
+   - For vertical deployment: antenna at top of enclosure
+   - For horizontal deployment: antenna toward open sky
+
+## Phase 5: Sensor Access and Integration
+
+If the device includes sensors, verify the enclosure supports them.
+
+1. **Environmental sensors** (temperature, humidity, pressure):
+   - Does the enclosure provide ventilation to the sensor?
+   - Is the sensor shielded from direct sunlight (radiation shield)?
+   - Is self-heating from the PCB isolated from the temperature
+     sensor?
+
+2. **External probe sensors** (soil moisture, waterproof temperature):
+   - Cable pass-through with strain relief?
+   - Sealed cable gland or grommet?
+   - Adequate cable bend radius inside the enclosure?
+
+3. **Light sensors**: Light pipe or transparent window aligned with
+   the sensor?
+
+4. **Conflicting requirements**: Does the design need both
+   ventilation (for air sensors) and sealing (for weather
+   protection)? If so, is a ventilation membrane (Gore-Tex type)
+   specified?
+
+## Phase 6: Manufacturing Feasibility
+
+Verify the enclosure can be manufactured with the specified process.
+
+1. **3D printing (FDM) feasibility**:
+   - Wall thickness ≥ 2mm (1.6mm absolute minimum for structural)
+   - No unsupported overhangs > 45° without designed-in supports
+   - Bridging distances ≤ 20mm without support
+   - Print orientation selected for strength (layer lines parallel
+     to primary stress direction)
+   - Tolerances appropriate for FDM (±0.3mm typical)
+
+2. **Assembly feasibility**:
+   - Can the PCB be inserted and fastened without special tools?
+   - Can cables be routed and connected in the available space?
+   - Can the lid be closed and sealed after assembly?
+   - Is the assembly sequence obvious or does it need documentation?
+
+3. **Material specification**: Is the material fully specified?
+   - Material type (not just "3D printed")
+   - Color (dark colors absorb more solar heat)
+   - Infill percentage (affects strength and thermal conductivity)
+   - Layer height (affects surface finish and seal quality)
+
+## Phase 7: Mounting and Deployment
+
+Verify the enclosure can be deployed in the target environment.
+
+1. **Mounting provisions**: Does the enclosure have mounting features?
+   - Screw tabs, zip-tie slots, DIN rail clips, magnetic mounts,
+     or pole/pipe clamps
+   - Are mounting features strong enough for the deployment method?
+   - Does mounting orientation preserve antenna performance?
+
+2. **Serviceability**: Can the device be serviced in the field?
+   - Battery replacement without full disassembly?
+   - USB access for firmware update?
+   - Can the lid be opened and resealed in the field?
+
+3. **Labeling**: Is there space for labels or markings?
+   - Regulatory markings (FCC ID, CE mark if applicable)
+   - Device identification (serial number, QR code)
+   - Orientation indicators ("THIS SIDE UP", antenna direction)