Plan 01: SourceDetailsPresenter Extraction

Objective

Extract ~50 lines of inline view logic from _details.html.erb (362 lines) into a SourceDetailsPresenter (V14). The template currently builds hashes with conditional formatting, number_with_precision calls, date formatting, and ternary operators -- all of which belong in a presenter.

Context

• @.claude/skills/rails-presenter/SKILL.md -- Presenter patterns with BasePresenter (SimpleDelegator)
• @.claude/skills/tdd-cycle/SKILL.md -- TDD red-green-refactor workflow
• @.claude/skills/sm-domain-model/SKILL.md -- Source model details (fetch_interval_minutes, fetch_circuit_open?, adaptive_fetching_enabled?)
• app/views/source_monitor/sources/_details.html.erb (362 lines) -- largest partial, contains inline formatting logic (lines 177-230)
• No existing BasePresenter in the engine -- check if one exists; if not, create one following the rails-presenter skill pattern
• Important: Do NOT modify sources_controller.rb -- instantiate the presenter inside _details.html.erb partial to avoid file conflicts with Plan 02 which modifies the controller's index action

Tasks

Task 1: Create BasePresenter if missing and write SourceDetailsPresenter tests (TDD red)

Check if app/presenters/source_monitor/base_presenter.rb exists. If not, create it (SimpleDelegator with ActionView helper includes).

Create test/presenters/source_monitor/source_details_presenter_test.rb:

• Test fetch_interval_display returns formatted string like "30 minutes (~0.50 hours)"
• Test circuit_state_label returns "Closed" when circuit not open, "Open until {date}" when open
• Test adaptive_interval_label returns "Auto" or "Fixed"
• Test details_hash returns a Hash with expected keys (Website, Fetch interval, Adaptive interval, Scraper, etc.)
• Test formatted_next_fetch_at handles nil and present timestamps
• Test formatted_last_fetched_at handles nil and present timestamps
• Test delegation to underlying Source model (name, feed_url, etc.)
• Use create_source! factory from existing test helpers

Task 2: Implement SourceDetailsPresenter

Create app/presenters/source_monitor/source_details_presenter.rb:

• Class SourceMonitor::SourceDetailsPresenter < SourceMonitor::BasePresenter
• Extract from _details.html.erb lines 177-230: fetch_interval_display, circuit_state_label, adaptive_interval_label
• details_hash method that builds the hash currently inlined in the template
• Date formatting helpers for fetch timestamps
• All formatting methods that currently use number_with_precision, conditional ternaries, and strftime

Task 3: Update template to use presenter

Modify app/views/source_monitor/sources/_details.html.erb:

• At the top of the partial, wrap the source local in the presenter: <% presenter = SourceMonitor::SourceDetailsPresenter.new(source) %>
• Replace inline hash building (lines 177-230) with presenter.details_hash calls
• Replace number_with_precision(source.fetch_interval_minutes / 60.0, ...) with presenter.fetch_interval_display
• Replace circuit state conditional logic with presenter.circuit_state_label
• Keep all HTML structure unchanged -- only swap logic calls
• Do NOT modify sources_controller.rb (Plan 02 modifies it for index action)

Task 4: Verify

• bin/rails test test/presenters/source_monitor/source_details_presenter_test.rb -- all pass
• bin/rails test test/controllers/source_monitor/sources_controller_test.rb -- all pass
• bin/rails test -- full suite passes
• bin/rubocop -- zero offenses