feat(capture): support per-app/per-URL capture exclusions

[rogerdigital]

Summary

• Add three optional [capture] config fields: excluded_window_title_patterns, excluded_app_names, excluded_bundle_ids
• Matching windows are skipped entirely — no AX query, no screenshot, no JSON, no FTS row
• Title patterns: case-insensitive substring match; app names and bundle IDs: case-insensitive exact match
• All default to empty lists, behaviour unchanged unless opted in

Usage

[capture]
excluded_window_title_patterns = ["Incognito", "Private Browsing", "InPrivate", "1Password"]
excluded_app_names             = ["Signal"]
excluded_bundle_ids            = ["com.apple.keychainaccess"]

Tests

• test_excluded_app_name_skips_capture — exact app name match
• test_excluded_bundle_id_skips_capture — exact bundle ID match
• test_excluded_title_pattern_skips_capture — substring title match
• test_non_excluded_window_proceeds — non-matching windows pass through
• test_exclusion_is_case_insensitive — case-insensitive matching
• test_exclusion_with_empty_title_does_not_match_pattern — empty title doesn't trigger pattern match

All 111 tests pass, ruff clean.

Closes #27

[gemini-code-assist]

Code Review

This pull request introduces privacy exclusion rules to skip window captures based on application names, bundle IDs, or window title patterns. It also improves datetime handling by ensuring that timestamps retrieved from the database or used in timeline aggregation are consistently timezone-aware. Feedback includes a suggestion to prevent empty strings in title patterns from matching all windows and a recommendation to omit window titles from logs when a capture is excluded to maintain privacy.

[gemini-code-assist]

If excluded_window_title_patterns contains an empty string, the any(p.lower() in title_lower ...) check will return True for any non-empty window title, effectively excluding all windows from capture. It is safer to ensure the pattern p is non-empty before performing the substring match.

Suggested change

	if any(p.lower() in title_lower for p in cfg.excluded_window_title_patterns):
	if any(p and p.lower() in title_lower for p in cfg.excluded_window_title_patterns):

[rogerdigital]

Fixed in b119274 — empty patterns are now skipped via p and p.lower() in title_lower.

[gemini-code-assist]

Logging the window title of an excluded window may inadvertently leak sensitive information that the user specifically intended to keep private by using the exclusion feature. Since these rules are often used for privacy-sensitive contexts (e.g., Incognito windows, password managers), it is safer to omit the title from the logs or only log the app name and bundle ID.

Suggested change

	logger.info(
	"capture skipped (excluded): app=%r title=%r bundle=%r",
	meta.app_name, meta.title[:60], meta.bundle_id,
	)
	logger.info(
	"capture skipped (excluded): app=%r bundle=%r",
	meta.app_name, meta.bundle_id,
	)

[rogerdigital]

Fixed in b119274 — removed title from the exclusion log, only app_name and bundle_id are logged.

[Xiao-ao-jiang-hu]

Please add documentation for the newly introduced configuration items in docs/config.md.

[rogerdigital]

Added in c297321 — documented all three fields under a new "Privacy exclusions" subsection in docs/config.md.